islands, from Rodriguez to the Seychelles; and this differs so remarkably
from the continent that it has been proposed to form a distinct primary
region for its reception. Its productions are indeed highly interesting;
since it possesses 3 families, and 2 sub-families of mammals peculiar to
itself, while almost all its genera are peculiar. Of these a few show
Oriental or Ethiopian affinities, but the remainder are quite isolated.
Turning to other classes of animals, we find that the birds are almost as
remarkable; but, as might be expected, a larger number of genera are common
to surrounding countries. More than 30 genera are altogether peculiar, and
some of these are so isolated as to require to be classed in separate
families or sub-families. The African affinity is however here more
strongly shown by the considerable number (13) of peculiar Ethiopian genera
which in Madagascar have representative species. There can be no doubt
therefore about Madagascar being more nearly related to the Ethiopian than
to any other region; but its peculiarities are so great, that, were it not
for its small size and the limited extent of its fauna, its claim to rank
as a separate region might not seem unreasonable. It is true that it is not
poorer in mammals than Australia; but that country is far more isolated,
and cannot be so decidedly and {75}naturally associated with any other
region as Madagascar can be with the Ethiopian. It is therefore the better
and more natural course to keep it as a sub-region; the peculiarities it
exhibits being of exactly the same kind as those presented by the Antilles,
by New Zealand, and even by Celebes and Ceylon, but in a much greater
degree.
_Oriental Region._--On account of the numerous objections that have been
made to naming a region from the least characteristic portion of it, and
not thinking "Malayan," proposed by Mr. Blanford, a good term, (as it has a
very circumscribed and definite meaning, and especially because the "Malay"
archipelago is half of it in the Australian region,) I propose to use the
word "Oriental" instead of "Indian," as being geographically applicable to
the whole of the countries included in the region and to very few beyond
it; as being euphonious, and as being free from all confusion with terms
already used in zoological geography. I trust therefore that it may meet
with general acceptance.
This small, compact, but rich and varied region, consists of all India and
China from the limits of the Palæarctic region; all the Malay peninsula and
islands as far east as Java and Baly, Borneo and the Philippine Islands;
and Formosa. It is positively characterized by possessing 12 peculiar
families of vertebrata; by 55 genera of land mammalia, and 165 genera of
land birds, altogether confined to it; these peculiar genera forming in
each case about one half of the total number it possesses.
_Sub-divisions of the Oriental region._--First we have the Indian
sub-region, consisting of Central India from the foot of the Himalayas in
the west, and south of the Ganges to the east, as far as a line drawn from
Goa curving south and up to the Kistna river; this is the portion which has
most affinity with Africa.
The second, or Ceylonese sub-region, consists of the southern extremity of
India with Ceylon; this is a mountainous forest region, and possesses
several peculiar forms as well as some Malayan types not found in the first
sub-region.
{76}Next we have the Indo-Chinese sub-region, comprising South China and
Burmah, extending westward along the Himalayan range to an altitude of
about 9,000 or 10,000 feet, and southward to Tavoy or Tenasserim.
The last is the Indo-Malayan sub-region, comprising the Peninsula of
Malacca and the Malay Islands to Baly, Borneo, and the Philippines.
On account of the absence from the first sub-region of many of the forms
most characteristic of the other three, and the number of families and
genera of mammalia and birds which occur in it and also in Africa, it has
been thought by some naturalists that this part of India has at least an
equal claim to be classed as a part of the Ethiopian region. This question
will be found fully discussed in Chapter XII. devoted to the Oriental
region, where it is shown that the African affinity is far less than has
been represented, and that in all its essential features Central India is
wholly Oriental in its fauna.
Before leaving this region a few words may be said about Lemuria, a name
proposed by Mr. Sclater for the site of a supposed submerged continent
extending from Madagascar to Ceylon and Sumatra, in which the Lemuroid type
of animals was developed. This is undoubtedly a legitimate and highly
probable supposition, and it is an example of the way in which a study of
the geographical distribution of animals may enable us to reconstruct the
geography of a bygone age. But we must not, as Mr. Blyth proposed, make
this hypothetical land one of our actual Zoological regions. It represents
what was probably a primary Zoological region in some past geological
epoch; but what that epoch was and what were the limits of the region in
question, we are quite unable to say. If we are to suppose that it
comprised the whole area now inhabited by Lemuroid animals, we must make it
extend from West Africa to Burmah, South China, and Celebes; an area which
it possibly did once occupy, but which cannot be formed into a modern
Zoological region without violating much more important affinities. If, on
the other hand, we leave out all those areas which undoubtedly belong to
other regions, we reduce Lemuria to Madagascar and its adjacent
{77}islands, which, for reasons already stated, it is not advisable to
treat as a primary Zoological region. The theory of this ancient continent
and the light it may throw on existing anomalies of distribution, will be
more fully considered in the geographical part of this work.
_Australian Region._--Mr. Sclater's original name seems preferable to
Professor Huxley's, "Austral-Asian;" the inconvenience of which alteration
is sufficiently shown by the fact that Mr. Blyth proposed to use the very
same term as an appropriate substitute for the "Indian region" of Mr.
Sclater. Australia is the great central mass of the region; it is by far
the richest in varied and highly remarkable forms of life; and it therefore
seems in every way fitted to give a name to the region of which it is the
essential element. The limits of this region in the Pacific are somewhat
obscure, but as so many of the Pacific Islands are extremely poor
zoologically, this is not of great importance.
_Sub-divisions of the Australian Region._--The first sub-region is the
Austro-Malayan, including the islands from Celebes and Lombock on the west
to the Solomon Islands on the east. The Australian sub-region comes next,
consisting of Australia and Tasmania. The third, or Polynesian sub-region,
will consist of all the tropical Pacific Islands, and is characterized by
several peculiar genera of birds which are all allied to Australian types.
The fourth, consists of New Zealand with Auckland, Chatham, and Norfolk
Islands, and must be called the New Zealand sub-region.
The extreme peculiarities of New Zealand, due no doubt to its great
isolation and to its being the remains of a more extensive land, have
induced several naturalists to suggest that it ought justly to form a
Zoological region by itself. But the inconveniences of such a procedure
have been already pointed out; and when we look at its birds as a whole
(they being the only class sufficiently well represented to found any
conclusion upon) we find that the majority of them belong to Australian
genera, and where the genera are peculiar they are most nearly related to
Australian types. The preservation in these islands {78}of a single
representative of a unique order of reptiles, is, as before remarked, of
the same character as the preservation of the _Proteus_ in the caverns of
Carniola; and can give the locality where it happens to have survived no
claim to form a primary Zoological region, unless supported by a tolerably
varied and distinctly characterized fauna, such as never exists in a very
restricted and insular area.
_Neotropical Region._--Mr. Sclater's original name for this region is
preserved, because change of nomenclature is always an evil; and neither
Professor Huxley's suggested alteration "Austro-Columbia," nor Mr.
Sclater's new term "Dendrogæa," appear to be improvements. The region is
essentially a tropical one, and the extra-tropical portion of it is not
important enough to make the name inappropriate. That proposed by Professor
Huxley is not free from the same kind of criticism, since it would imply
that the region was exclusively South American, whereas a considerable
tract of North America belongs to it. This region includes South America,
the Antilles and tropical North America; and it possesses more peculiar
families of vertebrates and genera of birds and mammalia than any other
region.
_Subdivisions of the Neotropical Region._--The great central mass of South
America, from the shores of Venezuela to Paraguay and Eastern Peru,
constitutes the chief division, and may be termed the Brazilian sub-region.
It is on the whole a forest country; its most remarkable forms are highly
developed arboreal types; and it exhibits all the characteristics of this
rich and varied continent in their highest development.
The second, or Chilian sub-region, consists of the open plains, pampas, and
mountains of the southern extremity of the continent; and we must include
in it the west side of the Andes as far as the limits of the forest near
Payta, and the whole of the high Andean plateaus as far as 4° of south
latitude; which makes it coincide with the range of the Camelidæ and
Chinchillidæ.
The third, or Mexican sub-region, consists of Central America and Southern
Mexico, but it has no distinguishing {79}characteristics except the absence
of some of the more highly specialized Neotropical groups. It is, however,
a convenient division as comprising the portion of the North American
continent which belongs zoologically to South America.
The fourth, or Antillean sub-region, consists of the West India islands
(except Trinidad and Tobago, which are detached portions of the continent
and must be grouped in the first sub-region); and these reproduce, in a
much less marked degree, the phenomena presented by Madagascar. Terrestrial
mammals are almost entirely wanting, but the larger islands possess three
genera which are altogether peculiar to them. The birds are of South
American forms, but comprise many peculiar genera. Terrestrial molluscs are
more abundant and varied than in any part of the globe of equal extent; and
if these alone were considered, the Antilles would constitute an important
Zoological region.
_Nearctic Region._--This region comprises all temperate North America and
Greenland. The arctic lands and islands beyond the limit of trees form a
transitional territory to the Palæarctic region, but even here there are
some characteristic species. The southern limit between this region and the
Neotropical is a little uncertain; but it may be drawn at about the Rio
Grande del Norte on the east coast, and a little north of Mazatlan on the
west; while on the central plateau it descends much farther south, and
should perhaps include all the open highlands of Mexico and Guatemala. This
would coincide with the range of several characteristic Nearctic genera.
_Distinction of the Nearctic from the Palæarctic Region._--The Nearctic
region possesses twelve peculiar families of vertebrates or one-tenth of
its whole number. It has also twenty-four peculiar genera of mammalia and
fifty-two of birds, in each case nearly one-third of all it possesses. This
proportion is very nearly the same as in the Palæarctic region, while the
number of peculiar families of vertebrata is very much greater. It has been
already seen that both Mr. Blyth and Professor Huxley are disposed to unite
this region with the Palæarctic, while Professor Newton, in his article on
birds in the new edition of the {80}Encyclopædia Britannica, thinks that as
regards that class it can hardly claim to be more than a sub-region of the
Neotropical. These views are mutually destructive, but it will be shown in
the proper place, that on independent grounds the Nearctic region can very
properly be maintained.
_Subdivisions of the Nearctic Region._--The sub-regions here depend on the
great physical features of the country, and have been in some cases
accurately defined by American naturalists. First we have the Californian
sub-region, consisting of California and Oregon--a narrow tract between the
Sierra Nevada and the Pacific, but characterized by a number of peculiar
species and by several genera found nowhere else in the region.
The second, or Rocky Mountain sub-region, consists of this great mountain
range with its plateaus, and the central plains and prairies to about 100°
west longitude, but including New Mexico and Texas in the South.
The third and most important sub-region, which may be termed the
Alleghanian, extends eastward to the Atlantic, including the Mississippi
Valley, the Alleghany Mountains, and the Eastern United States. This is an
old forest district, and contains most of the characteristic animal types
of the region.
The fourth, or Canadian sub-region, comprises all the northern part of the
continent from the great lakes to the Arctic ocean; a land of pine-forests
and barren wastes, characterized by Arctic types and the absence of many of
the genera which distinguish the more southern portions of the region.
_Observations on the series of Sub-regions._--The twenty-four sub-regions
here adopted were arrived at by a careful consideration of the distribution
of the more important genera, and of the materials, both zoological and
geographical, available for their determination; and it was not till they
were almost finally decided on, that they were found to be equal in number
throughout all the regions--four in each. As this uniformity is of great
advantage in tabular and diagrammatic presentations of the distribution of
the several families, I decided not to disturb it unless very strong
reasons should appear for adopting a greater or less number in any
particular case. Such however have not {81}arisen; and it is hoped that
these divisions will prove as satisfactory and useful to naturalists in
general as they have been to the author. Of course, in a detailed study of
any region much more minute sub-division may be required; but even in that
case it is believed that the sub-regions here adopted, will be found, with
slight modifications, permanently available for exhibiting general results.
I give here a table showing the proportionate richness and speciality of
each region as determined by its _families_ of vertebrates and _genera_ of
mammalia and birds; and also a general table of the regions and
sub-regions, arranged in the order that seems best to show their mutual
relations.
COMPARATIVE RICHNESS OF THE SIX REGIONS.
+-------------+-----------------+
| | VERTEBRATA. |
| REGIONS. |Families|Peculiar|
| | |families|
+-------------+--------+--------+
| Palæarctic | 136 | 3 |
| Ethiopian | 174 | 22 |
| Oriental | 164 | 12 |
| Australian | 141 | 30 |
| Neotropical | 168 | 44 |
| Nearctic | 122 | 12 |
+-------------+--------+--------+
+-------------+-----------------------+-----------------------+
| | MAMMALIA. | BIRDS. |
| REGIONS. |Genera|Peculiar| Per |Genera|Peculiar| Per |
| | |genera |centage| |genera |centage|
+-------------+------+--------+-------+------+--------+-------+
| Palæarctic | 100 | 35 | 35 | 174 | 57 | 33 |
| Ethiopian | 140 | 90 | 64 | 294 | 179 | 60 |
| Oriental | 118 | 55 | 46 | 340 | 165 | 48 |
| Australian | 72 | 44 | 61 | 298 | 189 | 64 |
| Neotropical | 130 | 103 | 79 | 683 | 576 | 86 |
| Nearctic | 74 | 24 | 32 | 169 | 52 | 31 |
+-------------+------+--------+-------+------+--------+-------+
TABLE OF REGIONS AND SUB-REGIONS.
+--------------+-----------------------------+--------------------------+
| Regions. | Sub-regions. | Remarks. |
+--------------+-----------------------------+--------------------------+
|I. Palæarctic |1. North Europe. | |
| |2. Mediterranean (or S. Eu.) |Transition to Ethiopian. |
| |3. Siberia. |Transition to Nearctic. |
| |4. Manchuria (or Japan) |Transition to Oriental. |
| | | |
|II. Ethiopian |1. East Africa. |Transition to Palæarctic. |
| |2. West Africa. | |
| |3. South Africa. | |
| |4. Madagascar. | |
| | | |
|III. Oriental |1. Hindostan(or Central Ind.)|Transition to Ethiopian. |
| |2. Ceylon. | |
| |3. Indo-China (or Himalayas) |Transition to Palæarctic. |
| |4. Indo-Malaya. |Transition to Australian. |
| | | |
|IV. Australian|1. Austro-Malaya. |Transition to Oriental. |
| |2. Australia. | |
| |3. Polynesia. | |
| |4. New Zealand. |Transition to Neotropical.|
| | | |
|V. Neotropical|1. Chili (or S. Temp. Am.) |Transition to Australian. |
| |2. Brazil. | |
| |3. Mexico (or Trop. N. Am.) |Transition to Nearctic. |
| |4. Antilles. | |
| | | |
|VI. Nearctic |1. California. | |
| |2. Rocky Mountains. |Transition to Neotropical.|
| |3. Alleghanies (or East U.S.)| |
| |4. Canada. |Transition to Palæarctic. |
+--------------+-----------------------------+--------------------------+
{83}CHAPTER V.
CLASSIFICATION AS AFFECTING THE STUDY OF GEOGRAPHICAL DISTRIBUTION.
A little consideration will convince us, that no inquiry into the causes
and laws which determine the geographical distribution of animals or plants
can lead to satisfactory results, unless we have a tolerably accurate
knowledge of the affinities of the several species, genera, and families to
each other; in other words, we require a natural classification to work
upon. Let us, for example, take three animals--_a_, _b_, and _c_--which
have a general external resemblance to each other, and are usually
considered to be really allied; and let us suppose that _a_ and _b_ inhabit
the same or adjacent districts, while c is found far away on the other side
of the globe, with no animals at all resembling it in any of the
intervening countries. We should here have a difficult problem to solve;
for we should have to show that the general laws by which we account for
the main features of distribution, will explain this exceptional case. But
now, suppose some comparative anatomist takes these animals in hand, and
finds that the resemblance of _c_ to _a_ and _b_ is only superficial, while
their internal structure exhibits marked and important differences; and
that _c_ really belongs to another group of animals, _d_, which inhabits
the very region in which _c_ was found--and we should no longer have
anything to explain. This is no imaginary case. Up to a very few years ago
a curious Mexican animal, _Bassaris astuta_, was almost always classed in
the civet family (Viverridæ), a group entirely {84}confined to Africa and
Asia; but it has now been conclusively shown by Professor Flower that its
real affinities are with the racoons (Procyonidæ), a group confined to
North and South America. In another case, however, an equally careful
examination shows, that an animal peculiar to the Himalayas (_Ælurus
fulgens_) has its nearest ally in the _Cercoleptes_ of South America. Here,
therefore, the geographical difficulty really exists, and any satisfactory
theory of the causes that have led to the existing distribution of living
things, must be able to account, more or less definitely, for this and
other anomalies. From these cases it will be evident, that if any class or
order of animals is very imperfectly known and its classification
altogether artificial, it is useless to attempt to account for the
anomalies its distribution may present; since those anomalies may be, to a
great extent, due to false notions as to the affinities of its component
species.
According to the laws and causes of distribution discussed in the preceding
chapters, we should find limited and defined distribution to be the rule,
universal or indefinite distribution to be the exception, in every natural
group corresponding to what are usually regarded as families and genera;
and so much is this the case in nature, that when we find a group of this
nominal rank scattered as it were at random over the earth, we have a
strong presumption that it is not natural; but is, to a considerable
extent, a haphazard collection of species. Of course this reasoning will
only apply, in cases where there are no unusual means of dispersal, nor any
exceptional causes which might determine a scattered distribution.
From the considerations now adduced it becomes evident, that it is of the
first importance for the success of our inquiry to secure a natural
classification of animals, especially as regards the families and genera.
The higher groups, such as classes and orders, are of less importance for
our purpose; because they are almost always widely and often universally
distributed, except those which are so small as to be evidently the nearly
extinct representatives of a once more extensive series of forms. We now
proceed to explain the classification to be adopted, as low down as the
series of families. To these, equivalent English {85}names are given
wherever they exist, in order that readers possessing no technical
knowledge, may form some conception of the meaning of the term "family" in
zoology.
The primary divisions of the animal kingdom according to two eminent modern
authorities are as follows:
HUXLEY. CARUS AND GERSTAEKER.
Classification of Animals Handbuch der Zoologie
(1869). (1868).
1. Protozoa }
} 1. Protozoa.
2. Infusoria }
3. Coelenterata 2. Coelenterata.
4. Annuloida 3. Echinodermata.
{ 4. Vermes.
5. Annulosa {
{ 5. Arthropoda.
6. Molluscoida 6. Molluscoida.
7. Mollusca 7. Mollusca.
8. Vertebrata 8. Vertebrata.
For reasons already stated it is only with the fifth, seventh, and eighth
of these groups that the present work proposes to deal; and even with the
fifth and seventh only partially and in the most general way.
The classes of the vertebrata, according to both the authors above quoted,
are: 1. Mammalia. 2. Aves. 3. Reptilia. 4. Amphibia. 5. Pisces, in which
order they will be taken here.
The sub-classes and orders of mammalia are as follows:
MAMMALIA.
HUXLEY (1869), FLOWER (1870). CARUS (1868).
{ 1. Primates.
{ 1. Primates {
{ { 5. Prosimii.
{ 2. Chiroptera 2. Chiroptera.
{ 3. Insectivora 3. Insectivora.
{ { 6. Carnivora.
{ 4. Carnivora {
{ { 7. Pinnipedia.
Monodelphia { 5. Cetacea }
{ } 12. Natantia.
{ 6. Sirenia }
{ {10. Artiodactyla.
{ 7. Ungulata {
{ {11. Perissodactyla.
{ 8. Proboscidea 9. Proboscidea.
{ 9. Hyracoidea 8. Lamnungia.
{ 10. Rodentia 4. Rodentia.
{ 11. Edentata 13. Bruta.
{
Didelphia 12. Marsupialia 14. Marsupialia.
Ornithodelphia 13. Monotremata 15. Monotremata.
{86}The above series of orders is arranged according to Professor Flower's
_Osteology of Mammalia_, and they will follow in this succession throughout
my work. Professor Huxley arranges the same orders in a different series.
In determining the manner in which the several orders shall be subdivided
into families, I have been guided in my choice of classifications mainly by
the degree of attention the author appears to have paid to the group, and
his known ability as a systematic zoologist; and in a less degree by
considerations of convenience as regards the special purposes of
geographical distribution. In many cases it is a matter of great doubt
whether a certain group should form several distinct families or be united
into one or two; but one method may bring out the peculiarities of
distribution much better than the other, and this is, in our case, a
sufficient reason for adopting it.
For the Primates I follow, with some modifications, the classification of
Mr. St. George Mivart given in his article "Apes" in the new edition of the
_Encyclopædia Britannica_, and in his paper in the _Proceedings of the
Zoological Society of London_, 1865, p. 547. It is as follows:
Order--PRIMATES, divided into two Sub-orders:
I. Anthropoidea.
II. Lemuroidea.
Sub-order--ANTHROPOIDEA.
Fam.
Hominidæ Man.
{ 1. Simiidæ Anthropoid Apes.
Simii { 2. Semnopithecidæ Old-world Monkeys.
{ 3. Cynopithecidæ Baboons and Macaques.
Cebii { 4. Cebidæ American Monkeys.
{ 5. Hapalidæ Marmosets.
Sub-order--LEMUROIDEA.
Fam.
6. Lemuridæ Lemurs.
7. Tarsiidæ Tarsiers.
8. Chiromyidæ Aye-ayes.
Omitting man (for reasons stated in the preface) the three first families
are considered by Professor Mivart to be sub-families of Simiidæ; but as
the geographical distribution of the Old World apes is especially
interesting, it is thought {87}better to treat them as families, a rank
which is claimed for the anthropoid apes by many naturalists.
As no good systematic work on the genera and species of bats has been yet
published, I adopt the five families as generally used in this country,
with the genera as given in the papers of Dr. J. E. Gray and Mr. Tomes. A
monograph by Dr. Peters has long been promised, and his outline arrangement
was published in 1865, but this will perhaps be materially altered when the
work appears.
Order--CHIROPTERA.
Fam.
Frugivora 9. Pteropidæ Fruit-eating Bats.
{Istiophora { 10. Phyllostomidæ Leaf-nosed Bats.
Insectivora { { 11. Rhinolophidæ Horse-shoe Bats.
{
{Gymnorhini { 12. Vespertilionidæ True Bats.
{ 13. Noctilionidæ Dog-headed Bats.
The genera of Chiroptera are in a state of great confusion, the names used
by different authors being often not at all comparable, so that the few
details given of the distribution of the bats are not trustworthy. We have
therefore made little use of this order in the theoretical part of the
work.
The osteology of the Insectivora has been very carefully worked out by
Professor Mivart in the _Jounral of Anatomy and Physiology_ (Vol. ii., p.
380), and I follow his classification as given there, and in the
_Proceedings of the Zoological Society_ (1871).
Order--INSECTIVORA.
Fam.
14. Galeopithecidæ Flying Lemurs.
15. Macroscelididæ Elephant Shrews.
16. Tupaiidæ Squirrel Shrews.
17. Erinaceidæ Hedgehogs.
18. Centetidæ Tenrecs.
19. Potamogalidæ Otter Shrew.
20. Chrysochloridæ Golden Moles.
21. Talpidæ Moles.
22. Soricidæ Shrews.
The next order, Carnivora, has been studied in detail by Professor Flower;
and I adopt the classification given by him in the _Proceedings of the
Zoological Society_, 1869, p. 4.
{88}Order--CARNIVORA.
Fam.
{ 23. Felidæ Cats, Lion, &c.
{ 24. Cryptoproctidæ Cryptoprocta.
{ Æluroidea { 25. Viverridæ Civets.
{ { 26. Protelidæ Aard-wolf.
{ { 27. Hyænidæ Hyænas.
{
Fissipedia { Cynoidea 28. Canidæ Dogs, Foxes, &c.
{
{ {29. Mustelidæ Weasels.
{ {30. Procyonidæ Racoons.
{ Arctoidea {31. Æluridæ Pandas.
{32. Ursidæ Bears.
{33. Otariidæ Eared Seals.
Pinnipedia {34. Trichechidæ Walrus.
{35. Phocidæ Seals.
The Cetacea is one of those orders the classification of which is very
unsettled. The animals comprising it are so huge, and there is so much
difficulty in preserving them, that only a very few species are known with
anything like completeness. A considerable number of genera and species
have been described or indicated; but as many of these are founded on
imperfect specimens of perhaps a single individual, it is not to be
wondered at that those few naturalists who occupy themselves with the study
of these large animals, cannot agree as to the proper mode of grouping them
into natural families. They are, however, of but little importance to us,
as almost all the species inhabit the ocean, and of only a few of them can
it be said that anything is accurately known of their distribution. I
therefore consider it best to follow Professor Carus, who makes a smaller
number of families; but I give also the arrangement of Dr. Gray in his
British Museum catalogue of whales and seals, as modified subsequently in
the _Proceedings of Zoological Society_, 1870, p. 772. The Zeuglodontidæ, a
family of extinct tertiary whales, are classed by Professors Owen and Carus
between Cetacea and Sirenia, while Professor Huxley considers them to have
been carnivorous and allied to the seals.
{89}Order--CETACEA.
Fam. (CARUS). Fam. (GRAY).
Sub-order I.-- { Balænidæ 36. Balænidæ.
Mystaceti. { Balænopteridæ 37. Balænopteridæ.
{ Catodontidæ 38. Catodontidæ.
{
{ { Hyperoodontidæ.
{ Hyperoodontidæ 39. { Epiodontidæ.
{ { Xiphiadæ.
{
Sub-order II.-- { Monodontidæ 40. (Part of Delphinidæ.)
Odontoceti {
{ { Platanistidæ.
{ { Iniadæ.
{ { Delphinidæ.
{ Delphinidæ 41. { Globiocephalidæ.
{ Orcadæ.
{ Belugidæ.
{ Pontoporiadæ.
Extinct family Zeuglodontidæ.
Order--SIRENIA.
The order Sirenia, comprising the sea-cows, consists of a single family:
Family 42. Manatidæ.
The extensive order Ungulata comprises the three orders Pachydermata,
Solidungula, and Ruminantia of the older naturalists. The following
classification is that now generally adopted, the only difference of
opinion being as to whether some of the groups should be classed as
families or sub-families, a matter of little importance for our purpose:
Order--UNGULATA.
Fam.
Perissodactyla or } 43. Equidæ Horses.
Odd-toed Ungulates } 44. Tapiridæ Tapirs.
45. Rhinocerotidæ Rhinoceros.
{ Suina { 46. Hippopotamidæ Hippopotamus.
{ { 47. Suidæ Swine.
{
Artiodactyla or { Tylopoda 48. Camelidæ Camels.
Even-toed Ungulates {
{ Tragulina 49. Tragulidæ Chevrotains.
{
{ { 50. Cervidæ Deer.
{ Pecora { 51. Camelopardidæ Giraffes.
{ 52. Bovidæ { Cattle, Sheep,
{ Antelopes, &c.
{90}The two next orders consist of but a single family each, viz.:
Order Fam.
PROBOSCIDEA 53. Elephantidæ Elephants.
HYRACOIDEA 54. Hyracidæ Rock-rabbits.
We now come to the Rodentia, a very extensive and difficult order, in which
there is still much difference of opinion as to the details of
classification, although the main outlines are pretty well settled. The
foundations of a true classification of this order were laid by Mr. G. R.
Waterhouse more than thirty years ago, and succeeding authors have done
little more than follow his arrangement with unimportant modifications.
Professor Lilljeborg, of Upsala, has however made a special study of this
group of animals, and has given an original and detailed classification of
all the genera. (_Systematisk Öfversigt af de Gnagande Däggdjuren, Glires.
Upsala, 1866._) I follow this arrangement with a few slight modifications
suggested by other naturalists, and which make it better adapted for the
purposes of this work.
Order--RODENTIA.
Fam.
{ 55. Muridæ Rats.
{ 56. Spalacidæ Mole-rats.
{ 57. Dipodidæ Jerboas.
{ 58. Myoxidæ Dormice.
{ Murina { 59. Saccomyidæ Pouched Rats.
{ (Waterhouse) { 60. Castoridæ Beavers.
{ { 61. Sciuridæ Squirrels.
Simplicidentati { { 62. Haploodontidæ Sewellels.
{
{ { 63. Chinchillidæ Chinchillas.
{ { 64. Octodontidæ Octodons.
{ Hystricina { 65. Echimyidæ Spiny Rats.
(Waterhouse) { 66. Cercolabidæ Tree Porcupines
{ 67. Hystricidæ Porcupines.
{ 68. Caviidæ Cavies.
Duplicidentati { Leporina { 69. Lagomyidæ Pikas.
{ (Waterhouse) { 70. Leporidæ Hares.
The Edentata have been classified by Mr. Turner, in the _Proceedings of the
Zoological Society_ (1851, p. 205), by Dr. Gray in the British Museum
Catalogue, and by Professor Carus in his _Handbuch_. The former takes a
middle course between {91}the numerous families of Dr. Gray, seven in
number, and the two families to which Professor Carus restricts the
existing species. I therefore follow Mr. Turner.
Order--EDENTATA.
Fam.
Bradypoda 71. Bradypodidæ Sloths.
{ 72. Manididæ Scaly Ant-eaters.
{ 73. Dasypodidæ Armadillos.
Entomophaga { 74. Orycteropodidæ Ant-bears.
{ 75. Myrmecophagidæ Ant-eaters.
The Marsupials have been well classified and described by Mr. Waterhouse in
the first volume of his _Natural History of Mammalia_, and his arrangement
is here followed. The suborders adopted by Professor Carus are also given.
Order--MARSUPIALIA.
Fam.
{ 76. Didelphidæ Opossums.
{ 77. Dasyuridæ Native Cats.
Rapacia (Wagner) { 78. Myrmecobiidæ Native Ant-eater.
{ 79. Peramelidæ Bandicoots.
Poephaga (Owen) 80. Macropodidæ Kangaroos.
Carpophaga (Owen) 81. Phalangistidæ Phalangers.
Rhizophaga (Owen) 82. Phascolomyidæ Wombats.
Order--MONOTREMATA.
The last order, the Monotremata, consist of two families, which Professor
Carus combines into one, but which it seems more natural to keep separate.
Fam.
83. Ornithorhynchidæ Duckbill.
84. Echidnidæ Echidna.
{92}BIRDS.
Birds are perhaps the most difficult to classify of all the divisions of
the vertebrata. The species and genera are exceedingly numerous, and there
is such a great uniformity in general structure and even in the details of
external form, that it is exceedingly difficult to find characters by which
orders and families can be characterised. For a long time the system of
Vigors and Swainson was followed; but this wholly ignored anatomical
characters and in many cases plainly violated well-marked affinities.
Characters derived from the form of the sternum, the scutellation of the
tarsi, and the arrangement of the feathers, have all assisted in
determining natural groups. More recently Professor Huxley has applied the
variations of the bony palate to the general arrangement of birds; and
still more recently Professor Garrod has studied certain leg-muscles for
the same purpose. The condition of the young as regards plumage, and even
the form, texture, and coloration of the egg, have also been applied to
solve doubtful cases of affinity; yet the problem is not settled, and it
will probably remain for another generation of ornithologists to determine
with any approach to accuracy what are the most natural divisions of the
class into orders and families. In a work like the present it is evidently
not advisable to adopt all the recent classifications; since experience has
shown that no arrangement in which one set of characters is mainly relied
on, long holds its ground. Such modifications of the old system as seem to
be well established will be adopted; but the older groups will be adhered
to in cases where the most recent classifications are open to doubt, or
seem inconvenient as separating families, which, owing to their similarity
in general structure, form and habits are best kept together for the
purposes of geographical distribution.
The old plan of putting the birds of prey at the head of the class, is now
almost wholly given up; both because they are not {93}the most highly
organised, but only one of the most specialised forms of birds, and because
their affinities are not with the Passeres, but rather with the cormorants
and some other of the aquatic groups. The Passeres therefore are placed
first; and the series of families is begun by the thrushes, which are
certainly the most typical and generally well-organised form of birds.
Instead of the Scansores and Fissirostres of the older authors, the order
Picariæ, which includes them both, is adopted, but with some reluctance; as
the former are, generally speaking, well marked and strongly contrasted
groups, although certain families have been shown to be intermediate. In
the Picariæ are included the goat-suckers, swifts, and humming-birds,
sometimes separated as a distinct order, Macrochires. The parrots and the
pigeons form each a separate order. The old groups of Grallæ and Anseres
are preserved, as more convenient than breaking them up into widely
separated parts; for though the latter plan may in some cases more strictly
represent their affinities, its details are not yet established, nor is it
much used by ornithologists. In accordance with these views the following
is the series of orders and families of birds adopted in this work:
Class--AVES.
Orders.
1. Passeres { Including the great mass of the smaller birds--Crows,
{ Finches, Flycatchers, Creepers, Honeysuckers, &c., &c.
2. Picariæ { Including Woodpeckers, Cuckoos, Toucans, Kingfishers,
{ Swifts, &c., &c.
3. Psittaci Parrots only.
4. Columbæ Pigeons and the Dodo.
5. Gallinæ Grouse, Pheasants, Curassows, Mound-builders, &c.
6. Opisthocomi The Hoazin only.
7. Accipitres Eagles, Owls, and Vultures.
8. Grallæ Herons, Plovers, Rails, &c.
9. Anseres Gulls, Ducks, Divers, &c.
10. Struthiones Ostrich, Cassowary, Apteryx, &c.
The Passeres consist of fifty families, which may be arranged and grouped
in series as follows. It must however be remembered that the first family
in each series is not always that which is most allied to the last family
of the preceding series. All extensive natural groups consist of divergent
or branching alliances, which renders it impossible to arrange the whole in
one continuous series.
{94}A.--TYPICAL OR TURDOID PASSERES.
1. Turdidæ Thrushes.
2. Sylviidæ Warblers.
3. Timaliidæ Babblers.
4. Panuridæ Reedlings.
5. Cinclidæ Dippers.
6. Troglodytidæ Wrens.
7. Chamæidæ
8. Certhiidæ Creepers.
9. Sittidæ Nuthatches.
10. Paridæ Tits.
11. Liotrichidæ Hill-tits.
12. Phyllornithidæ Green Bulbuls.
13. Pycnonotidæ Bulbuls.
14. Oriolidæ Orioles.
15. Campephagidæ Caterpillar-shrikes.
16. Dicruridæ Drougos.
17. Muscicapidæ Flycatchers.
18. Pachycephalidæ Thick-heads.
19. Laniidæ Shrikes.
20. Corvidæ Crows.
21. Paradiseidæ Paradise-birds.
22. Meliphagidæ Honey-suckers.
23. Nectarineidæ Sun-birds.
B.--TANAGROID PASSERES.
24. Dicæidæ Flower-peckers.
25. Drepanididæ
26. Cærebidæ Sugar-birds.
27. Mniotiltidæ Wood-warblers.
28. Vireonidæ Greenlets.
29. Ampelidæ Waxwings.
30. Hirundinidæ Swallows.
31. Icteridæ Hangnests.
32. Tanagridæ Tanagers.
33. Fringillidæ Finches.
C.--STURNOID PASSERES.
34. Ploceidæ Weaver-birds.
35. Sturnidæ Starlings.
36. Artamidæ Swallow-shrikes.
37. Alaudidæ Larks.
38. Motacillidæ Wagtails.
D.--FORMICAROID PASSERES.
39. Tyrannidæ Tyrants.
40. Pipridæ Manakins.
41. Cotingidæ Chatterers.
42. Phytotomidæ Plant-cutters.
43. Eurylæmidæ Broad-bills.
44. Dendrocolaptidæ American Creepers.
45. Formicariidæ Ant-thrushes.
46. Pteroptochidæ {95}
47. Pittidæ Pittas.
48. Paictidæ
E.--ANOMALOUS PASSERES.
49. Menuridæ Lyre-birds.
50. Atrichidæ Scrub-birds.
The preceding arrangement is a modification of that proposed by myself in
the _Ibis_ (1874, p. 406). The principal alterations are adding the
families Panuridæ and Sittidæ in series A, commencing series B with
Dicæidæ; bringing Vireonidæ next to the allied American family Mniotiltidæ;
and placing Motacillidæ in series C next to Alaudidæ. At the suggestion of
Professor Newton I place Menuridæ and Atrichidæ apart from the other
Passeres, as they both possess striking peculiarities of anatomical
structure.
The heterogeneous families constituting the order Picariæ may be
conveniently arranged as follows:
{ 51. Picidæ Woodpeckers.
{ 52. Yungidæ Wrynecks.
{ 53. Indicatoridæ Honey-guides.
Sub-order-- { 54. Megalæmidæ Barbets.
Scansores. { 55. Rhamphastidæ Toucans.
{ 56. Musophagidæ Plantain-eaters.
{ 57. Coliidæ Colies.
{ 58. Cuculidæ Cuckoos.
Intermediate 59. Leptosomidæ The Leptosoma.
{ 60. Bucconidæ Puff-birds.
{ 61. Galbulidæ Jacamars.
{ 62. Coraciidæ Rollers.
{ 63. Meropidæ Bee-eaters.
{ 64. Todidæ Todies.
{ 65. Momotidæ Motmots.
{ 66. Trogonidæ Trogons.
Sub-order-- { 67. Alcedinidæ Kingfishers.
Fissirostres. { 68. Bucerotidæ Hornbills.
{ 69. Upupidæ Hoopoes.
{ 70. Irrisoridæ Promerops.
{ 71. Podargidæ Frog-mouths.
{ 72. Steatornithidæ The Guacharo.
{ 73. Caprimulgidæ Goatsuckers.
{ 74. Cypselidæ Swifts.
{ 75. Trochilidæ Humming-birds.
{96}The Psittaci or parrot tribe are still in a very unsettled state of
classification; that recently proposed by Professor Garrod differing widely
from the arrangement adopted in Dr. Finsch's monograph of the order. Taking
advantage of the researches of these and other authors, the following
families are adopted as the most convenient in the present state of our
knowledge:
76. Cacatuidæ The Cockatoos.
77. Platycercidæ The Broad-tailed Paroquets of Australia.
78. Palæornithidæ The Oriental Parrots and Paroquets.
79. Trichoglossidæ The Brush-tongued Paroquets and Lories.
80. Conuridæ The Macaws and their allies.
81. Psittacidæ The African and South American Parrots.
82. Nestoridæ The Nestors of New Zealand.
83. Stringopidæ The Owl-parrots of New Zealand.
The Columbæ, or pigeons, are also in a very unsatisfactory state as regards
a natural classification. The families, sub-families, and genera proposed
by various authors are very numerous, and often quite irreconcilable. I
therefore adopt only two families; and generally follow Mr. G. R. Gray's
hand-list for the genera, except where trustworthy authorities exist for a
different arrangement. The families are:
84. Columbidæ Pigeons and Doves.
85. Dididæ The extinct Dodo and allies.
The Gallinæ, or game-birds, may be divided into seven families:
Fam. Sub-fam.
86. Pteroclidæ Sand-grouse.
87. Tetraonidæ Partridges and Grouse.
{ Pavoninæ Peafowl.
{ Lophophorinæ Tragopans, &c.
{ Phasianinæ Pheasants.
88. Phasianidæ { Euplocaminæ Fire-backed Pheasants, &c.
{ Gallinæ Jungle-fowl.
{ Meleagrinæ Turkeys.
{ Numidinæ Guinea-fowl.
89. Turnicidæ Hemipodes.
90. Megapodiidæ Mound-makers.
{ Cracinæ Curassows.
91. Cracidæ { Penelopinæ Guans.
{ Oreophasinæ Mountain-pheasant.
92. Tinamidæ Tinamous.
{97}The Opisthocomi consist of one family containing a single species, the
"Hoatzin" of Guiana.
Family 93. Opisthocomidæ.
The Accipitres, or birds of prey, which were long considered to be the
highest and most perfect order of birds, are now properly placed lower down
in the series, their affinities being more with the aquatic than with the
perching birds. The following is the arrangement adopted by Mr. Sharpe in
his recently published British Museum catalogue of diurnal birds of prey:--
Sub-orders. Fam. Sub-families.
{ Vulturinæ Vultures.
{ 94. Vulturidæ { Sarcorhamphinæ Turkey-buzzards.
{
Falcones { 95. Serpentariidæ
{
{ { Polyborniæ Caracaras.
{ { Accipitrinæ Hawks.
{ 96. Falconidæ { Buteoninæ Buzzards.
{ Aquilinæ Eagles.
{ Falconinæ Falcons.
Pandiones 97. Pandionidæ Fishing-eagles.
Striges 98. Strigidæ Owls.
The Grallæ or Grallatores are in a very unsettled state. The following
series of families is in accordance with the views of some of the best
modern ornithologists:
99. Rallidæ Rails, &c.
100. Scolopacidæ Sandpipers and Snipes
101. Chionididæ Sheath-bills.
102. Thinocoridæ Quail-snipes.
103. Parridæ Jacanas.
104. Glareolidæ Pratincoles.
105. Charadriidæ Plovers.
106. Otididæ Bustards.
107. Gruidæ Cranes.
108. Cariamidæ Cariamas.
109. Aramidæ Guaraunas.
110. Psophiidæ Trumpeters.
111. Eurypygidæ Sun-bitterns.
112. Rhinochoetidæ Kagus.
113. Ardeidæ Herons.
114. Plataleidæ Spoonbills and Ibis.
115. Ciconiidæ Storks.
116. Palamedeidæ Screamers.
117. Phænicopteridæ Flamingoes.
{98}The Anseres or Natatores are almost equally unsettled. The flamingoes
are usually placed in this order, but their habits best assort with those
of the waders.
Fam.
118. Anatidæ Duck and Geese.
119. Laridæ Gulls.
120. Procellariidæ Petrels.
121. Pelecanidæ Pelicans.
122. Spheniscidæ Penguins.
123. Colymbidæ Divers.
124. Podicipidæ Grebes.
125. Alcidæ Auks.
The last order of birds is the Struthiones or Ratitæ, considered by many
naturalists to form a distinct sub-class. It consists of comparatively few
species, either living or recently extinct.
Fam.
{ 126. Struthionidæ Ostriches.
Living { 127. Casuariidæ Cassowaries.
{ 128. Apterygidæ Apteryx.
{ 129. Dinornithidæ Dinornis.
Extinct { 130. Palapterygidæ Palapteryx.
{ 131. Æpyornithidæ Æpyornis.
REPTILES.
In reptiles I follow the classification of Dr. Günther as given in the
_Philosophical Transactions_, vol. clvii., p. 625. He divides the class
into five orders as follows:--
Sub-classes. Orders.
{ 1. Ophidia Serpents.
I. Squamata { 2. Lacertilia Lizards.
{ 3. Rhyncocephalina The Hatteria.
II. Loricata 4. Crocodilia Crocodiles.
III. Cataphracta 5. Chelonia Tortoises.
In the arrangement of the families comprised in each of these orders I also
follow the arrangement of Dr. Günther and Dr. J. E. Gray, as given in the
British Museum Catalogue, or as modified by the former gentleman who has
kindly given me much personal information.
{99}The Ophidia, or Snakes, form the first order and are classified as
follows:--
Fam.
{ 1. Typhlopidæ }
{ 2. Tortricidæ }
{ 3. Xenopeltidæ } Burrowing Snakes.
{ 4. Uropeltidæ }
{ 5. Calamaridæ Dwarf ground-snakes.
{ 6. Oligodontidæ.
{ 7. Colubridæ Colubrine Snakes.
{ 8. Homalopsidæ Fresh-water Snakes.
{ 9. Psammophidæ Desert-snakes.
Innocuous Snakes { 10. Rachiodontidæ.
{ 11. Dendrophidæ Tree-snakes.
{ 12. Dryiophidæ Whip-snakes.
{ 13. Dipsasidæ Nocturnal tree-snakes.
{ 14. Scytalidæ
{ 15. Lycodontidæ Fanged ground-snakes.
{ 16. Amblycephalidæ Blunt-heads.
{ 17. Pythonidæ Pythons.
{ 18. Erycidæ Sand-snakes.
{ 19. Acrochordidæ Wart-snakes.
{ 20. Elapidæ Cobras, &c.
Venomous Colubrine { 21. Dendraspididæ.
Snakes { 22. Atractaspididæ.
{ 23. Hydrophidæ Sea-snakes.
{ 24. Crotalidæ Pit-vipers.
Viperine Snakes { 25. Viperidæ True vipers.
The second order, Lacertilia, are arranged as follows:--
Fam.
26. Trogonophidæ }
27. Chirotidæ }
28. Amphisbænidæ } Amphisbænians.
29. Lepidosternidæ }
30. Varanidæ Water Lizards.
31. Helodermidæ.
32. Teidæ Teguexins.
33. Lacertidæ } Land Lizards.
34. Zonuridæ }
35. Chalcidæ.
36. Anadiadæ.
37. Chirocolidæ.
38. Iphisadæ.
39. Cercosauridæ.
40. Chamæsauridæ.
41. Gymnopthalmidæ Gape-eyed Scinks.
42. Pygopodidæ Two-legged Lizards.
43. Aprasiadæ.
44. Lialidæ. {100}
45. Scincidæ Scinks.
46. Ophiomoridæ Snake-lizards.
47. Sepidæ Sand-lizards.
48. Acontiadæ.
49. Geckotidæ Geckoes.
50. Iguanidæ Iguanas.
51. Agamidæ Fringed Lizards.
52. Chameleonidæ Chameleons.
The third order, Rhyncocephalina consists of a single family:--
53. Rhyncocephalidæ The Hatteria of New Zealand.
The fourth order, Crocodilia or Loricata, consists of three families:--
54. Gavialidæ Gavials.
55. Crocodilidæ Crocodiles.
56. Alligatoridæ Alligators.
The fifth order, Chelonia, consists of four families:--
57. Testudinidæ Land and fresh-water Tortoises.
58. Chelydidæ Fresh-water Turtles.
59. Trionychidæ Soft Turtles.
60. Cheloniidæ Sea Turtles.
AMPHIBIA.
In the Amphibia I follow the classification of Professor Mivart, as given
for a large part of the order in the _Proceedings of the Zoological
Society_ for 1869. For the remainder I follow Dr. Strauch, Dr. Günther, and
a MSS. arrangement kindly furnished me by Professor Mivart.
The class is first divided into three groups or orders, and then into
families as follows:--
{101}Order I.--PSEUDOPHIDIA.
Fam.
1. Cæciliadæ Cæcilia.
Order II.--BATRACHIA URODELA.
2. Sirenidæ Siren.
3. Proteidæ Proteus.
4. Amphiumidæ Amphiuma.
5. Menopomidæ Giant Salamanders.
6. Salamandridæ Salamanders and Newts.
Order III.--BATRACHIA ANOURA.
7. Rhinophrynidæ }
8. Phryniscidæ }
9. Hylaplesidæ } Toads.
10. Bufonidæ }
11. Xenorhinidæ }
12. Engystomidæ }
13. Bombinatoridæ }
14. Plectromantidæ } Frogs.
15. Alytidæ }
16. Pelodryadæ }
17. Hylidæ } Tree Frogs.
18. Polypedatidæ }
19. Ranidæ } Frogs.
20. Discoglossidæ }
21. Pipidæ } Tongueless
22. Dactylethridæ } Toads.
FISHES.
These are arranged according to the classification of Dr. Günther, whose
great work "The British Museum Catalogue of Fishes," has furnished almost
all the material for our account of the distribution of the class.
In that work all existing fishes are arranged in six sub-classes and
thirteen orders. A study of the extraordinary _Ceratodus_ from Australia
has induced Dr. Günther to unite three of his sub-classes; but as his
catalogue will long remain a handbook for every student of fishes, it seems
better to follow the arrangement there given, indicating his later views by
bracketing together the groups he now thinks should be united.
-----------------------------------------+---------+--------------- {102}
Sub-class. Order. |Families.| Remarks.
-----------------------------------------+---------+------------------
{ 1. Acanthopterygii | 47 | Gasterosteidæ to
{ | | Notacanthi.
{ 2. Do. Pharyncognathi | 5 | Pomacentridæ to
{ | | Chromidæ.
Ganoidei { 3. Acanthini | 6 | Gadopsidæ to
======== { | | Pleuronectidæ.
{Teleostei { 4. Physostomi | 29 | Siluridæ to
{ { | | Pegasidæ.
{ { 5. Lophobranchii | 2 | Solenostomidæ and
{ { | | Syngnathidæ.
{ { 6. Plectognathi | 2 | Sclerodermi and
{ { | | Gymnodontes.
{ | |
{Dipnoi 7. Sirenoidei | 1 | Sirenoidei.
{ | |
{ { 8. Holostei | 3 | Amiidæ to
{ { | | Lepidosteidæ.
{Ganoidei { 9. Chondrostei | 2 | Accipenseridæ and
{ | | Polydontidæ.
| |
Chondropterygii { 10. Holocephala | 1 | Chimæridæ.
{ 11. Plagiostomata | 15 | Carchariidæ to
| | Myliobatidæ.
| |
Cyclostomata 12. Marsipobranchii | 2 | Petromyzontidæ and
| | Myxinidæ.
| |
Leptocardii 13. Cirrhostomi | 1 | Cirrhostomi.
+---------+
Total 116 families.
-----------------------------------------------------------------------
INSECTS.
The families and genera of insects are so immensely numerous, probably
exceeding fifty-fold those of all other land animals, that for this cause
alone it would be impossible to enter fully into their distribution. It is
also quite unnecessary, because many of the groups are so liable to be
transported by accidental causes, that they afford no useful information
for our subject; while others are so obscure and uninteresting that they
have been very partially collected and studied, and are for this reason
equally ineligible. I have therefore selected a few of the largest and most
conspicuous families, which have been so assiduously collected in every
part of the globe, and so carefully studied at home, as to afford valuable
materials for comparison with the vertebrate groups, when we have made due
allowance for the dependence of many insects on peculiar forms of
vegetation, and the facility with which many of them are transported either
in the egg, larva, or perfect state, by winds, currents, and other less
known means.
I confine myself then, almost exclusively, to the sixteen families of
Diurnal Lepidoptera or butterflies, and to six of the most extensive,
conspicuous, and popular families of Coleoptera. {103}The number of species
of Butterflies is about the same as that of Birds, while the six families
of Coleoptera selected, comprise more than twenty thousand species, far
exceeding the number of all other vertebrates. These families have all been
recently catalogued, so that we have very complete information as to their
arrangement and distribution.
LEPIDOPTERA DIURNA, OR BUTTERFLIES.
Fam.
1. Danaidæ.
2. Satyridæ.
3. Elymniidæ.
4. Morphidæ.
5. Brassolidæ.
6. Acræidæ.
7. Heliconidæ.
8. Nymphalidæ.
9. Libythæidæ.
10. Nemeobiidæ.
11. Eurygonidæ.
12. Erycinidæ.
13. Lycænidæ.
14. Pieridæ.
15. Papilionidæ.
16. Hesperidæ.
COLEOPTERA, OR BEETLES.
Fam.
1. Cicindelidæ Tiger-beetles.
2. Carabidæ Ground-beetles.
3. Lucanidæ Stag-beetles.
4. Cetoniidæ Rose-chafers.
5. Buprestidæ Metallic Beetles.
6. Longicornia Long-horned Beetles.
The above families comprise the extensive series of ground beetles
(Carabidæ) containing about 9,000 species, and the Longicorns, which are
nearly as numerous and surpass them in variety of form and colour as well
as in beauty. The Cetoniidæ and Buprestidæ are among the largest and most
brilliant of beetles; the Lucanidæ are pre-eminent for remarkable form, and
the Cicindelidæ for elegance; and all the families are especial favourites
with entomologists, so that the whole earth has been ransacked to procure
fresh species.
Results deduced from a study of these will, therefore, fairly represent the
phenomena of distribution of Coleoptera, and, as they are very varied in
their habits, perhaps of insects in general.
{104}MOLLUSCA.
The Mollusca are usually divided into five classes as follows:--
Classes.
I. Cephalopoda Cuttle-fish.
II. Gasteropoda Snails and aquatic Univalves.
III. Pteropoda Oceanic Snails.
IV. Brachiopoda Symmetrical Bivalves.
V. Conchifera Unsymmetrical Bivalves.
The Gasteropoda and Conchifera alone contain land and freshwater forms, and
to these we shall chiefly confine our illustrations of the geographical
distribution of the Mollusca. The classification followed is that of Dr.
Pfeiffer for the Operculata and Dr. Von Martens for the Helicidæ. The
families chiefly referred to are:--
Class II.--GASTEROPODA.
Order 2.--Pulmonifera.
Fam.
{ 1. Helicidæ.
{ 2. Limacidæ.
{ 3. Oncidiadæ.
In-operculata { 4. Limnæidæ.
{ 5. Auriculidæ.
{ 6. Aciculidæ.
{ 7. Diplommatinidæ.
Operculata { 8. Cyclostomidæ.
{ 9. Helicinidæ.
PART II.
_ON THE DISTRIBUTION OF EXTINCT ANIMALS._
{107}CHAPTER VI.
THE EXTINCT MAMMALIA OF THE OLD WORLD.
Although it may seem somewhat out of place to begin the systematic
treatment of our subject with extinct rather than with living animals, it
is necessary to do so in order that we may see the meaning and trace the
causes of the existing distribution of animal forms. It is true, that the
animals found fossil in a country are very generally allied to those which
still inhabit it; but this is by no means universally the case. If it were,
the attempt to elucidate our subject by Palæontology would be hopeless,
since the past would show us the same puzzling diversities of faunas and
floras that now exist. We find however very numerous exceptions to this
rule, and it is these exceptions which tell us of the past migrations of
whole groups of animals. We are thus enabled to determine what portion of
the existing races of animals in a country are descendants of its ancient
fauna, and which are comparatively modern immigrants; and combining these
movements of the forms of life with known or probable changes in the
distribution of land and sea, we shall sometimes be able to trace
approximately the long series of changes which have resulted in the actual
state of things. To gain this knowledge is our object in studying the
"Geographical Distribution of Animals," and our plan of study must be
determined, mainly, by the facilities it affords us for attaining this
object. In discussing the countless details of distribution we shall meet
with in our survey of the zoological regions, we shall often find it useful
to refer to the evidence we possess of the range of the group in question
in {108}past times; and when we attempt to generalise the phenomena on a
large scale, with the details fresh in our memory, we shall find a
reference to the extinct faunas of various epochs to be absolutely
necessary.
The degree of our knowledge of the Palæontology of various parts of the
world is so unequal, that it will not be advisable to treat the subject
under each of our six regions. Yet some subdivision must be made, and it
seems best to consider separately the extinct animals of the Old and of the
New Worlds. Those of Europe and Asia are intimately connected, and throw
light on the past changes which have led to the establishment of the three
great continental Old World regions, with their various subdivisions. The
wonderful extinct fauna recently discovered in North America, with what was
previously known from South temperate America, not only elucidates the past
history of the whole continent, but also gives indications of the mutual
relations of the eastern and western hemispheres.
The materials to be dealt with are enormous; and it will be necessary to
confine ourselves to a general summary, with fuller details on those points
which directly bear upon our special subject. The objects of most interest
to the pure zoologist and to the geologist--those strange forms which are
farthest removed from any now living--are of least interest to us, since we
aim at tracing the local origin or birthplace of existing genera and
families; and for this purpose animals whose affinities with living forms
are altogether doubtful, are of no value whatever.
The great mass of the vertebrate fossils of the tertiary period consist of
mammalia, and this is precisely the class which is of most value in the
determination of zoological regions. The animals of the secondary period,
though of the highest interest to the zoologist are of little importance to
us; both because of their very uncertain affinities for any existing
groups, and also because we can form no adequate notion of the distribution
of land and sea in those remote epochs. Our great object is to trace back,
step by step, the varying distribution of the chief forms of life; and to
deduce, wherever possible, the physical changes which must have accompanied
or caused such changes. {109}The natural division of our subject therefore
is into geological periods. We first go back to the Post-Pliocene period,
which includes that of the caves and gravels of Europe containing flint
implements, and extends back to the deposit of the glacial drift in the
concluding phase of the glacial epoch. Next we have the Pliocene period,
divided into its later portion (the Newer Pliocene) which includes the
Glacial epoch of the northern hemisphere; and its earlier portion (the
Older Pliocene), represented by the red and coralline crag of England, and
deposits of similar age in the continent. During this earlier epoch the
climate was not very dissimilar from that which now prevails; but we next
get evidence of a still earlier period, the Miocene, when a warmer climate
prevailed in Europe, and the whole fauna and flora were very different.
This is perhaps the most interesting portion of the tertiary deposits, and
furnishes us with the most valuable materials for our present study.
Further back still we have the Eocene period, with apparently an almost
tropical climate in Europe; and here we find a clue to some of the most
puzzling facts in the distribution of living animals. Our knowledge of this
epoch is however very imperfect; and we wait for discoveries that will
elucidate some of the mystery that still hangs over the origin and
migrations of many important families. Beyond this there is a great chasm
in the geological record as regards land animals; and we have to go so far
back into the past, that when we again meet with mammalia, birds, and
land-reptiles, they appear under such archaic forms that they cease to have
any local or geographical significance, and we can only refer them to
wide-spread classes and orders. For the purpose of elucidating geographical
distribution, therefore, it is, in the present state of our knowledge,
unnecessary to go back beyond the tertiary period of geology.
The remains of Mammalia being so much more numerous and important than
those of other classes, we shall at first confine ourselves almost
exclusively to these. What is known of the birds, reptiles, and fishes of
the tertiary epoch will be best indicated by a brief connected sketch of
their fossils in all parts of the globe, which we shall give in a
subsequent chapter.
{110}_Historic Period._--In tracing back the history of the organic world
we find, even within the limits of the historical period, that some animals
have become extinct, while the distribution of others has been materially
changed. The _Rytina_ of the North Pacific, the dodo of Mauritius, and the
great auk of the North Atlantic coasts, have been exterminated almost in
our own times. The kitchen-middens of Denmark contain remains of the
capercailzie, the _Bos primigenius_, and the beaver. The first still
abounds farther north, the second is extinct, and the third is becoming so
in Europe. The great Irish elk, a huge-antlered deer, probably existed
almost down to historic times.
_Pleistocene or Post-Pliocene Period._--We first meet with proofs of
important changes in the character of the European fauna, in studying the
remains found in the caverns of England and France, which have recently
been so well explored. These cave-remains are probably all subsequent to
the Glacial epoch, and they all come within the period of man's occupation
of the country. Yet we find clear proofs of two distinct kinds of change in
the forms of animal life. First we have a change clearly traceable to a
difference of climate. We find such arctic forms as the rein-deer, the
musk-sheep, the glutton, and the lemming, with the mammoth and the woolly
rhinoceros of the Siberian ice-cliffs, inhabiting this country and even the
south of France. This is held to be good proof that a sub-arctic climate
prevailed over all Central Europe; and this climate, together with the
continental condition of Britain, will sufficiently explain such a
southward range of what are now arctic forms.
But together with this change we have another that seems at first sight to
be in an exactly opposite direction. We meet with numerous animals which
now only inhabit Africa, or South Europe, or the warmer parts of Asia. Such
are, large felines--some closely related to the lion (_Felis spelæa_),
others of altogether extinct type (_Machairodus_) and forming the extreme
development of the feline race;--hyænas; horses of two or more species; and
a hippopotamus. If we go a little further back, to the remains furnished by
the gravels and brick-earths, we still find the same association of forms.
The reindeer, the glutton, {111}the musk-sheep, and the woolly rhinoceros,
are associated with several other species of rhinoceros and elephant; with
numerous civets, now abundant only in warm countries; and with antelopes of
several species. We also meet here with a great extension of range of forms
now limited to small areas. The Saiga antelope of Eastern Europe occurs in
France, where wild sheep and goats and the chamois were then found,
together with several species of deer, of bear, and of hyæna. A few extinct
genera even come down to this late period, such as the great sabre-toothed
tiger, _Machairodus_; _Galeotherium_, a form of Viverridæ; _Palæospalax_,
allied to the mole; and _Trogontherium_, a gigantic form of beaver,
We find then, that even at so early a stage of our inquiries we meet with a
problem in distribution by no means easy to solve. How are we to explain
the banishment from Europe in so short a space of time (geologically
speaking) of so many forms of life now characteristic of warmer countries,
and this too during a period when the climate of Central Europe was itself
becoming warmer? Such a change must almost certainly have been due to
changes of physical geography, which we shall be better able to understand
when we have examined the preceding Pliocene period. We may here notice,
however, that so far as we yet know, this great recent change in the
character of the fauna is confined to the western part of the Palæarctic
region. In caves in the Altai Mountains examined by Prof. Brandt, a great
collection of fossil bones was discovered. These comprised the Siberian
rhinoceros and mammoth, and the cave hyæna; but all the others, more than
thirty distinct species, are now living in or near the same regions. We may
perhaps impute this difference to the fact that the migration of Southern
types into this part of Siberia was prevented by the great mountain and
desert barrier of the Central Asiatic plateau; whereas in Europe there was
at this time a land connection with Africa. Post-pliocene deposits and
caverns in Algeria have yielded remains resembling the more southern
European types of the Post-pliocene period, but without any admixture of
Arctic forms; showing, as we might expect, that the glacial cold did not
{112}extend so far south. We have here remains of _Equus_, _Bos_,
_Antilope_, _Hippopotamus_, _Elephas_, _Rhinoceros_, _Ursus_, _Canis_, and
_Hyæna_, together with _Phacochoerus_, an African type of swine which has
not occurred in the European deposits.
It is perhaps to the earlier portion of this period that the
_Merycotherium_ of the Siberian drift belongs. This was an animal related
to the living camel, thus supporting the view that the _Camelidæ_ are
essentially denizens of the extra-tropical zone.
PLIOCENE PERIOD.
_Primates._--We here first meet with evidence of the existence of monkeys
in Central Europe. Species of _Macacus_ have left remains not only in the
Newer Pliocene of the Val d'Arno in Italy, but in beds of the same age at
Grays in Essex; while _Semnopithecus_ and _Cercopithecus_, genera now
confined to the Oriental and Ethiopian regions respectively, have been
found in the Pliocene deposits of the South of France and Italy.
_Carnivora._--Most of the genera which occurred in the Post-Pliocene are
found here also, and many of the same species. Few new forms appear, except
_Hyænarctos_, a large bear with characters approaching the hyænas, and
_Pristiphoca_, a new form of seal, both from the Older Pliocene of France;
and _Galecynus_, a fox-like animal intermediate between _Canis_ and
_Viverra_, from the Pliocene of Oeninghen in Switzerland.
_Cetacea._--Species of _Balæna_, _Physeter_, and _Delphinus_ occur in the
Older Pliocene of England and France, and with these the remains of many
extinct forms, _Balænodon_ and _Hoplocetus_ (Balænidæ); _Belemnoziphius_
and _Choneziphius_ (Hyperoodontidæ), and _Halitherium_, an extinct form of
the next order--Sirenia, now confined to the tropics, although the recently
extinct _Rytina_ of the N. W. Pacific shows that it is also adapted for
temperate climates.
_Ungulata._--The Pliocene deposits are not very rich in this order. The
horses (_Equidæ_) are represented by the genus _Equus_; and here we first
meet with _Hipparion_, in which small lateral toes appear. Both genera
occur in British deposits of this age. {113}A more interesting fact for us
is the occurrence of the genus _Tapirus_ in the Newer Pliocene of France
and in the older beds of both France and England, since this genus is now
isolated in the remotest parts of the eastern and western tropics. The
genera _Rhinoceros_, _Hippopotamus_, and _Sus_, occur here as in the
preceding epoch.
We next come to the deer genus (_Cervus_), which appears to have been at
its maximum in this period, no less than eight species occurring in the
Norwich Crag, and Forest-beds. Among the Bovidæ, the antelopes, ox, and
bison, are the only forms represented here, as in the Post-Pliocene period.
Passing on to the Proboscidea, we find three species of elephants and two
of _Mastodon_ preserved in European beds of this period, all distinct from
those of Post-Pliocene times.
_Rodentia._--In this order we find representatives of many living European
forms; as _Cricetus_ (hamster), _Arvicola_ (vole), _Castor_ (beaver),
_Arctomys_ (marmot), _Hystrix_ (porcupine), _Lepus_ (hare), and _Lagomys_
(pika); and a few that are extinct, the most important being _Chalicomys_,
allied to the beaver; and _Issiodromys_, said to come nearest to the
remarkable _Pedetes_ of South Africa, both found in the Pliocene formations
of France.
_General Conclusions as to Pliocene and Post-Pliocene Faunas of
Europe._--This completes the series of fossil forms of the Pliocene
deposits of Europe. They show us that the presence of numerous large
carnivora and ungulates (now almost wholly tropical) in the Post-Pliocene
period, was due to no exceptional or temporary cause, but was the result of
a natural succession from similar races which had inhabited the same
countries for long preceding ages. In order to understand the vast periods
of time covered by the Pliocene and Post-Pliocene formations, the works of
Sir Charles Lyell must be studied. We shall then come to see, that the
present condition of the fauna of Europe is wholly new and exceptional. For
a long succession of ages, various forms of monkeys, hyænas, lions, horses,
hipparions, tapirs, rhinoceroses, hippopotami, elephants, mastodons, deer,
and antelopes, together {114}with almost all the forms now living, produced
a rich and varied fauna such as we now see only in the open country of
tropical Africa. During all this period we have no reason to believe that
the climate or other physical conditions of Europe were more favourable to
the existence of these animals than now. We must look upon them, therefore,
as true indigenes of the country, and their comparatively recent extinction
or banishment as a remarkable phenomenon for which there must have been
some adequate cause. What this cause was we can only conjecture; but it
seems most probable that it was due to the combined action of the Glacial
period, and the subsidence of large areas of land once connecting Europe
with Africa. The existence, in the small island of Malta, of no less than
three extinct species of elephant (two of very small stature), of a
gigantic dormouse, an extinct hippopotamus, and other mammalia, together
with the occurrence of remains of hippopotamus in the caves of Gibraltar,
indicate very clearly that during the Pliocene epoch, and perhaps during a
considerable part of the Post-Pliocene, a connection existed between South
Europe and North Africa in at least these two localities. At the same time
we have every reason to believe that Britain was united to the Continent,
what is now the German Ocean constituting a great river-valley. During the
height of the Glacial epoch, these large animals would probably retire into
this Mediterranean land and into North Africa, making annual migrations
northwards during the summer. But as the connecting land sank and became
narrower and narrower, the migrating herds would diminish, and at last
cease altogether; and when the glacial cold had passed away would be
altogether prevented from returning to their former haunts.
MIOCENE PERIOD.
We now come to a period which was wonderfully rich in all forms of life,
and of which the geological record is exceptionally complete. Various
lacustrine, estuarine, and other deposits in Europe, North India, and North
America, have furnished such a {115}vast number of remains of extinct
mammalia, as to solve many zoological problems, and to throw great light on
the early distribution and centres of dispersal of various groups of
animals. In order to show the bearing of these remains on our special
subject, we will first give an account of the extinct fauna of Greece, of
the Upper Miocene period; since this, being nearest to Africa and Asia,
best exhibits the relations of the old European fauna to those countries.
We shall then pass to the Miocene fauna of France and Central Europe; and
conclude with the remarkable Siwalik and other Indian extinct faunas, which
throw an additional light on the early history of the animal life of the
great old-world continents.
_Extinct Animals of Greece._
These are from the Upper Miocene deposits at Pikermi, near Athens, and were
collected by M. Gaudry a few years ago. They comprise ten living and
eighteen extinct genera of mammalia, with a few birds and reptiles.
_Primates._--These are represented by _Mesopithecus_, a genus believed to
be intermediate between the two Indian genera of monkeys, _Semnopithecus_
and _Macacus_.
_Carnivora._--These were abundant. Of _Felis_ there were four species,
ranging from the size of a cat to that of a jaguar, a large _hyæna_, and a
large weasel (_Mustela_). Besides these there were the huge _Machairodus_,
larger than any existing lion or tiger, and with enormously developed
canine teeth; _Hyænictis_ and _Lycæna_, extinct forms of Hyænidæ;
_Thalassictis_=_Ictitherium_, an extinct genus of Viverridæ but with
resemblances to the hyænas, represented by three species, some of which
were larger than any existing Viverridæ; _Promephytis_, an extinct form of
Mustelidæ, having resemblances to the European marten, to the otters, and
to the S. African _Zorilla_; and lastly, _Simocyon_, an extraordinary
carnivore of the size of a small panther, but having the canines of a cat,
the molars of a dog, and the jaws shaped like those of a bear.
_Ungulata._--These are numerous and very _interesting_. The Equidæ are
represented by the three-toed _Hipparion_, which {116}continued to exist
till the Older Pliocene period. There are three large species of
_Rhinoceros_, as well as a species of the extinct genus _Leptodon_ of
smaller size. Remains of a very large wild boar (_Sus_) were found. Very
interesting is the occurrence of a species of giraffe (_Camelopardalis_) as
tall as the African species but more slender; and also an extinct genus
_Helladotherium_, not quite so tall as the giraffe but much more robust,
and showing some approach to the Antilopidæ in its dentition. Antelopes
were abundant, ranging from the size of the gazelle to that of the largest
living species. Three or four seem referable to living genera, but the
majority are of extinct types, and are classed in the genera _Palæotragus_,
_Palæoryx_, _Tragocerus_, and _Palæoreas_; while _Dremotherium_ is an
ancient generalized form of _Cervidæ_ or deer.
_Proboscidea._--These are represented by two species of _Mastodon_, and two
of _Dinotherium_, an extraordinary extinct form supposed to be, to some
extent, intermediate between the elephants and the aquatic manatees
(_Sirenia_.)
_Rodentia._--This order is represented by a species of _Hystrix_, larger
than living porcupines.
_Edentata._--This order, now almost confined to South America, was
represented in the Miocene period by several European species.
_Ancylotherium_ and _Macrotherium_, belonging to an extinct family but
remotely allied to the African ant-bear (_Orycteropus_), occur in Greece.
_Birds._--Species of _Phasianus_ and _Gallus_ were found; the latter
especially interesting as being now confined to India.
_Reptiles._--These are few and unimportant, consisting of a tortoise
(_Testudo_) and a large lizard allied to _Varanus_.
_Summary of the Miocene Fauna of Greece._--Although we cannot consider that
the preceding enumeration gives us by any means a complete view of the
actual inhabitants of this part of Europe during the later portion of the
Miocene period, we yet obtain some important information. The resemblance
that appeared in the Pliocene fauna of Europe, to that of the open country
of tropical Africa, is now still more remarkable. We {117}not only find
great felines, surpassing in size and destructive power the lions and
leopards of Africa, with hyænas of a size and in a variety not to be
equalled now, but also huge rhinoceroses and elephants, two forms of
giraffes, and a host of antelopes, which, from the sample here obtained,
were probably quite as numerous and varied as they now are in Africa.
Joined with this abundance of antelopes we have the absence of deer, which
probably indicates that the country was open and somewhat of a desert
character, since there were deer in other parts of Europe at this epoch.
The occurrence of but a single species of monkey is also favourable to this
view, since a well-wooded country would most likely have supplied many
forms of these animals.
_Miocene Fauna of Central and Western Europe._
We have now to consider the Miocene fauna of Europe generally, of which we
have very full information from numerous deposits of this age in France,
Switzerland, Italy, Germany, and Hungary.
_Primates._--Three distinct forms of monkeys have been found in Europe--in
the South of France, in Switzerland, and Wurtemberg; one was very like
_Colobus_ or _Semnopithecus_; the others--_Pliopithecus_ and
_Dryopithecus_--were of higher type, and belonged to the anthropomorphous
apes, being nearest to the genus _Hylobates_ or gibbons. Both have occurred
in the South of France. The _Dryopithecus_ was a very large animal (equal
to the gorilla), and M. Lartet considers that in the character of its
dentition it approached nearer to man than any of the existing anthropoid
apes.
_Insectivora._--These small animals are represented by numerous remains
belonging to four families and a dozen genera. Of _Erinaceus_ (hedgehog)
several species are found in the Upper Miocene; and in the Lower Miocene of
Auvergne two extinct genera of the same family--_Amphechinus_ and
_Tetracus_--have been discovered. Several species of _Talpa_ (mole) occur
in the Upper Miocene of France, while the extinct _Dinylus_ is from
Germany, and _Palæospalax_ from the Lower Miocene of the Isle of
{118}Wight. The Malayan family Tupaiidæ or squirrel-shrews, is believed to
be represented by _Oxygomphus_, a fossil discovered in South Germany
(Wiesenau) by H. von Meyer. The Soricidæ or shrews, are represented by
several extinct genera--_Plesiosorex_, _Mysarachne_ and _Galeospalax_; as
well as by _Amphisorex_ and _Myogale_ still living. _Echinogale_, a genus
of Centetidæ now confined to Madagascar, is said to occur in the Lower
Miocene of Auvergne, a most interesting determination, if correct, as it
would form a transition to the _Solenodon_ of the Antilles belonging to the
same family; but I am informed by Prof. Flower that the affinities of the
animals described under this name are very doubtful.
_Carnivora._--Besides _Felis_ and _Machairodus_, which extend back to the
Upper Miocene, there are two other genera of Felidæ, _Pseudælurus_ in the
Upper Miocene of France, and _Hyænodon_, which occurs in the Upper and
Lower Miocene of France, named from some resemblance in its teeth to the
hyænas, and considered by some Palæontologists to form a distinct family,
Hyænodontidæ. The Viverridæ, or civets, were very numerous, consisting of
the living genus _Viverra_, and three extinct
forms--_Thalassictis_=_Ictitherium_, as large as a panther, and
_Soricictis_, a smaller form, occurring both in France and Hungary. Of
_Hyænidæ_, there was the living genus _Hyæna_, and the extinct _Hyænictis_,
which has occurred in Hungary as well as in Greece. The Canidæ, or wolf and
fox family, were represented by _Pseudocyon_, near to _Canis_; _Hemicyon_,
intermediate between dogs and gluttons; and _Amphicyon_, of which several
species occur in the Upper and Lower Miocene of France, some of them larger
than a tiger. The Mustelidæ, or weasels, were represented by five genera,
the existing genera _Lutra_ (otter) and _Mustela_ (weasel);
_Potamotherium_, an extinct form of otter; _Taxodon_, allied to the badger
and otter; _Palæomephitis_ in Germany, and the _Promephytis_ (already
noticed) in Greece. The bears were represented only by _Hyænarctos_, which
has been noticed as occurring in the Pliocene, and first appears in the
Upper Miocene of France. Seals are represented by a form resembling the
Antarctic _Otaria_, remains of which occur in the Upper Miocene of France.
{119}_Cetacea_ (whales).--These occur frequently in the Miocene deposits,
four living, and five extinct genera having been described; but these
marine forms are not of much importance for our purpose.
_Sirenia_ (sea-cows).--These are represented by two extinct genera,
_Halitherium_ and _Trachytherium_. Several species of the former have been
discovered, but the latter has occurred in France only, and its affinities
are doubtful.
_Ungulata._--Horses are represented by _Hipparion_ and _Anchitherium_, the
latter occurring in both Upper and Lower Miocene and Eocene; while
_Hipparion_, which is more nearly allied to living horses, first appears in
the Upper Miocene and continues in the Pliocene.
_Hippotherium_, in the Upper Miocene of the Vienna basin, forms a
transition to _Paloplotherium_, an Eocene genus of Tapiridæ or
Palæotheridæ. Tapirs, allied to living forms, occur in both Upper and Lower
Miocene. Rhinoceroses are still found in the Upper Miocene, and here first
appear the four-toed hornless rhinoceros, _Acerotherium_. The Suidæ (swine)
are rather numerous. _Sus_ (wild boar) continued as far back as the Upper
Miocene; but now there first appear a number of extinct forms which have
been named _Hyotherium_, _Palæochoerus_, _Choeromorus_, all of a small or
moderate size; _Hyopotamus_, nearly as large as a tapir; and
_Anthracotherium_, nearly the size of a hippopotamus and, according to Dr.
Leidy, the type of a distinct family. _Listriodon_, from the Upper Miocene
of the Vienna basin, is sometimes classed with the tapirs.
We now come to a well-marked new family of Artiodactyle or even-toed
Ungulata, the _Anoplotheriidæ_, which consisted of more slender long-tailed
animals, allied to the swine but with indications of a transition towards
the camels. The only genera that appear in the Miocene formation are,
_Chalicotherium_, nearly as large as a rhinoceros, of which three species
have been found in Germany and France; and _Synaphodus_, known only from
its teeth, which differ somewhat from those of the _Anoplotherium_ which
appears earlier in the Eocene formation. Another extinct family,
_Amphimericidæ_ or _Xiphodontidæ_, is represented by two {120}genera,
_Cainotherium_ and _Microtherium_, in the Miocene of France. They were of
very small size, and are supposed to be intermediate between the Suidæ and
Tragulidæ.
The Camelopardalidæ, or giraffes, were represented in Europe in Miocene
times by the gigantic _Helladotherium_, which has been found in the south
of France, and in Hungary, as well as in Greece. The chevrotains
(Tragulidæ) are represented by the extinct genus _Hyomoschus_.
The Cervidæ do not seem to have appeared in Europe before the Upper Miocene
epoch, when they were represented by _Dorcatherium_ and _Amphimoschus_,
allied to _Moschus_, and also by true _Cervus_, as well as by small allied
forms, _Dremotherium_, _Amphitragalus_ (in the Lower Miocene),
_Micromeryx_, _Palæomeryx_, and _Dicrocerus_.
The Bovidæ, or hollow-horned ruminants, were not well represented in
Central Europe in Miocene times. There were no sheep, goats, or oxen, and
only a few antelopes of the genus _Tragocerus_, and one allied to
_Hippotragus_; and these all lived in the Upper Miocene period, as did the
more numerous forms of Greece.
_Proboscidea._--The true elephants do not extend back to the Miocene
period, but they are represented by the Mastodons, which had less complex
teeth. These first appear in the Upper Miocene of Europe, five species
being known from France, Germany, Switzerland, and Greece. _Dinotherium_,
already noticed as occurring in Greece, extended also to Germany and
France, where remains of three species have been found.
_Rodentia._--A considerable number of generic forms of this order have been
obtained from the Miocene strata. The principal genera are _Cricetodon_,
allied to the hamsters, numerous in both the Upper and Lower Miocene period
of France; _Myoxus_ (the dormice) in France, and an allied genus,
_Brachymys_, in Germany. The beavers were represented by the still living
genus _Castor_, and the extinct _Steneofiber_ in France. The squirrels by
the existing _Scuirus_ and _Spermophilus_; and by extinct forms, _Lithomys_
and _Aulacodon_, in Germany, the latter resembling the African genus
_Aulacodes_. The hares, by _Lagomys_ and an {121}extinct form _Titanomys_.
Besides these, remains referred to the South American genera, _Cavia_
(cavy) and _Dasyprocta_ (agouti), have been found, the former in the Upper
Miocene of Switzerland, the latter in the Lower Miocene of Auvergne.
_Palæomys_, allied to the West Indian _Capromys_, has been found in the
same deposits; as well as _Theridomys_, said by Gervais to be allied to
_Anomalurus_ and _Echimys_, the former now living in W. Africa, the latter
in S. America.
_Edentata._--These are only represented by the _Macrotherium_ and
_Ancylotherium_ of the Grecian deposits, the former occurring also in
France and Germany in Upper Miocene strata.
_Marsupials_.--These consist of numerous species related to the opossums
(_Didelphys_), but separated by Gervais under the name _Peratherium_. They
occur in both Upper and Lower Miocene beds.
_Upper Miocene Deposits of the Siwalik Hills and other Localities in N. W.
India._
These remarkable fresh-water deposits form a range of hills at the foot of
the Himalayas, a little south of Simla. They were investigated for many
years by Sir P. Cautley and Dr. Falconer, and add greatly to our knowledge
of the early fauna of the Old World continent.
_Primates_.--Remains of the genera _Semnopithecus_ and _Macacus_ were
found, with other forms of intermediate character; and some teeth indicated
animals allied to the orang-utan of Borneo, and of similar size.
_Carnivora_.--These consisted of species of _Felis_ and _Machairodus_ of
large size; _Hyæna_, _Canis_, _Mellivora_, and an allied genus _Ursitaxus_;
_Ursus_, in the deposits of the Nerbudda valley (of Pliocene age);
_Hyænarctos_ as large as the cave bear; _Amphicyon_ of the size of a polar
bear (in the deposits of the Indus valley, west of Cashmere); _Lutra_, and
an extinct allied genus _Enhydrion_.
_Ungulata_.--These are very numerous, and constitute the most important
feature of this ancient fauna. Horses are represented by a species of
_Equus_ from the Siwalik Hills and the Irawaddy {122}deposits in Burmah,
and by two others from the Pliocene of the Nerbudda Valley; while
_Hippotherium_--a slender, antelope-like animal, found in the Siwalik Hills
and in Europe--is supposed to form a transition from the Equidæ to the
Tapiridæ. These latter are found in the Upper Indus deposits, where there
is a species of _Tapirus_, and one of an extinct genus _Antelotherium_. Of
_Rhinoceros_, five extinct species have been found--in the Siwalik Hills,
in Perim Island, and one at an elevation of 16,000 feet in the deserts of
Thibet. _Hippopotamus_ occurs in the Pliocene of the Nerbudda, and is
represented in the older Miocene deposits by _Hexaprotodon_, of which three
species have been found in various parts of India. Another remarkable
genus, _Merycopotamus_, connects _Hippopotamus_ with _Anthracotherium_, one
of the extinct European forms allied to the swine. These last are
represented by several large species of _Sus_, and by the extinct European
genus _Choerotherium_.
The extinct Anoplotheridæ are represented by a species of the European
genus _Chalicotherium_, larger than a horse.
An extinct camel, larger than the living species, was found in the Siwalik
Hills.
Three species of deer (_Cervus_) have been found in the Siwaliks, and one
in the Nerbudda deposits.
A large and a small species of giraffe (_Camelopardalis_) were found in the
Siwalik Hills and at Perim Island.
The Bovidæ are represented by numerous species of _Bos_, and by the extinct
genera _Hemibos_ and _Amphibos_. There are also three species of antelopes,
one of which is allied to the African _Alcephalus_.
We now come to an extraordinary group of extinct animals, probably forming
a new family intermediate between the antelope and the giraffe. The
_Sivatherium_ was an enormous four-horned ruminant, larger than a
rhinoceros. It had a short trunk like a tapir, the lower horns on the
forehead were simple, the upper pair palmated. The _Bramatherium_, an
allied form from Perim Island, showed somewhat more affinity for the
giraffe.
_Proboscidea._--No less than seven species of elephants and four {123}of
mastodons ranged over India, their remains being found in all the deposits
from the Siwalik Hills to Burmah. A large _Dinotherium_ has also been found
at Perim Island.
_Reptiles._--Many remains of birds were found, but these have not been
determined. Reptiles were numerous and interesting, the most remarkable
being the huge tortoise, _Colossochelys_, whose shell was twelve feet long
and head and neck eight feet more. Other small tortoises of the genera
_Testudo_, _Emys_, _Trionyx_ and _Emydida_ were found, the Emys being a
living species. There were three extinct and one living species of
crocodile, and one of them was larger than any now living. The only other
reptile of importance was a large lizard of the genus _Varanus_.
_General Observations on the Miocene faunas of Europe and Asia._--Comparing
the three faunas of approximately the same period, and allowing for the
necessarily imperfect record of each, we find a wonderful similarity of
general type over the enormous area between France on the west and the
Irawaddy river in Burmah on the east. We may even extend our comparison to
Northern China, where remains of _Hyæna_, _Tapir_, _Rhinoceros_,
_Chalicotherium_, and _Elephas_, have been recently found, closely
resembling those from the Miocene or Pliocene deposits of Europe or India,
and showing that the Palæarctic region had then the same great extent from
west to east that it has now. Of about forty genera comprised in the Indian
Miocene fauna, no less than twenty-seven inhabited Central and Western
Europe during the same epoch. The Indian Miocene fossils are much what we
should expect as the forerunners of the existing fauna, the giraffes and
hippopotami being the only additions from the present Ethiopian fauna. The
numerous forms of the restricted bovine type, show that these probably
originated in India; while the monkeys appear to be altogether of Oriental
types.
In Europe, however, we meet with a totally different assemblage of animals
from those that form the existing fauna. We find apes and monkeys, many
large Felidæ, numerous civets {124}and hyænas, tapirs, rhinoceros,
hippopotamus, elephants, giraffes, and antelopes, such as now characterise
the tropics of Africa and Asia. Along with these we meet with less familiar
types, showing relations with the Centetidæ of Madagascar, the Tupaiidæ of
the Malay Islands, the _Capromys_, of the West Indies, and the _Echimys_ of
South America. And besides all these living types we have a host of extinct
forms,--ten or twelve genera allied to swine; nine genera of tapir-like
animals; four of horses; nine of wolves; with many distinct forms of the
long-extinct families of Anoplotheridæ, Xiphodontidæ, and the edentate
Macrotheridæ. It is almost certain that during the Miocene period Europe
was not only far richer than it is now in the higher forms of life, but not
improbably richer than any part of the globe now is, not excepting tropical
Africa and tropical Asia.
EOCENE PERIOD.
The deposits of Eocene age are less numerous, and spread over a far more
limited area, than those of the Miocene period, and only restricted
portions of them furnish any remains of land animals. Our knowledge of the
Eocene mammalian fauna is therefore very imperfect and will not occupy us
long, as most of the new types it furnishes are of more interest to the
zoologist than to the student of distribution. Some of the Eocene mammalia
of Europe are, however, of interest in comparison with those of North
America of the same age; while others show that ancestral types of groups
now confined to Australia or to South America, then inhabited Europe.
_Primates._--The only undoubted Eocene examples of this order, are the
_Cænopithecus lemuroides_ from the Jura, which has points of resemblance to
the South American marmosets and howlers, and also to the Lemuridæ; and a
cranium recently discovered in the Department of Lot (S.W. France),
undoubtedly belonging to the Lemuridæ, and which most resembles that of the
West African "Potto" (_Perodicticus_). This discovery has led to another,
for it is now believed that remains formerly {125}referred to the
Anoplotheridæ (_Adapis_ and _Aphelotherium_ from the Upper Eocene of Paris)
were also Lemurs. Some remains from the Lower Eocene of Suffolk were at
first supposed to be allied to _Macacus_, but were subsequently referred to
the Ungulate, _Hyracotherium_. There is still, however, some doubt as to
its true affinities.
_Chiroptera._--In the Upper Eocene of Paris remains of bats have been
found, so closely resembling living forms as to be referred to the genus
_Vespertilio_.
_Carnivora._--The only feline remains, are those of _Hyænodon_ in the Upper
Eocene of Hampshire, and _Pterodon_, an allied form from beds of the same
age in France; with _Ælurogale_, found in the South of France in deposits
of phosphate of lime of uncertain age, but probably belonging to this
period. Viverridæ (civets) are represented by two genera, _Tylodon_, the
size of a glutton from the Upper Eocene, and _Palæonyctis_, allied to
_Viverra_, from the Middle Eocene of France. The Canidæ (wolves and foxes)
appear to have been the most ancient of the existing types of Carnivora,
five genera being represented by Eocene remains. Of these, _Galethylax_ and
_Cyotherium_ were small, and with the existing genus _Canis_ are found in
the Upper Eocene of France. _Arctocyon_, about the size of a wolf, is a
very ancient and generalised form of carnivore which can not be placed in
any existing family. It is found in the Lower Eocene of France, and is thus
the oldest known member of the Carnivora.
_Ungulata._--These are more numerous. Equidæ (horses) are represented by
the Miocene _Anchitherium_ in the Lower, and by a more ancient form,
_Anchilophus_, in the Middle Eocene of France. Tapiridæ and Palæotheridæ
were very numerous. _Palæotherium_ and the allied genus _Paloplotherium_,
were abundant in France and England in Upper Eocene times. They somewhat
resembled the tapir, with affinities for the horse and rhinoceros. A new
genus, _Cadurcotherium_, allied to the rhinoceros and equally large, has
been found in the same deposits of phosphate of lime as the lemur and
_Ælurogale_. In the Middle Eocene of both England and France are found
_Lophiodon_ allied to the tapir, {126}but in some of the species reaching a
larger size; _Propalæotherium_ and _Pachynolophus_ of smaller size and
having affinities for the other genera named; and _Plagiolophus_, a small,
slender animal which Professor Huxley thinks may have been a direct
ancestor of the horse. In the Lower Eocene we meet with _Coryphodon_, much
larger than the tapir, and armed with large canine teeth; _Pliolophus_, a
generalised type, allied to the tapir and horse; and _Hyracotherium_, a
small animal from the Lower Eocene of England, remotely allied to the
tapir.
Among the Artiodactyla, or even-toed ungulates, the swine are represented
by several extinct genera, of moderate or small size--_Acotherium_,
_Choeropotamus_, _Cebochoerus_ and _Dichobune_, all from the Upper and the
last also from the Middle Eocene of France; but _Eutelodon_, from the
phosphate of lime deposits is large. The _Dichobune_ was the most
generalised type, presenting the characters of many of the other genera
combined, and was believed by Dr. Falconer to approach the musk-deer. The
_Cainotherium_ of the Miocene also occurs here, and an allied genus
_Plesiomeryx_ from the same deposits as _Euteledon_.
The Eocene Anoplotheridæ were numerous. The _Anoplotherium_ was a two-toed,
long-tailed Pachyderm, ranging from the size of a hog to that of an ass;
the allied _Eurytherium_ was four-toed; and there are one or two others of
doubtful affinity. All are from the Upper Eocene of France and England.
_Rodentia._--Remains referred to the genera _Myoxus_ (dormouse) and
_Sciurus_ (squirrel) have been found in the Upper Eocene of France; as well
as _Plesiarctomys_, an extinct genus between the marmots and squirrels. The
Miocene _Theridomys_ is also found here.
_Marsupials._--The _Didelphys_ (opossum) of Cuvier, now referred to an
extinct genus _Peratherium_, is found in the Upper Eocene of France and
England.
_General Considerations on the Extinct Mammalian Fauna of Europe._--It is a
curious fact that no family, and hardly a genus, of European mammalia
occurs in the Pliocene deposits, without extending back also into those of
Miocene age. There are, {127}however, a few groups which, seem to be late
developments or recent importations into the Palæarctic region, as they
occur only in Post-Pliocene deposits. The most important of these are the
badger, glutton, elk, reindeer, chamois, goat, and sheep, which only occur
in caves and other deposits of Post-Pliocene age. Camels only occur in the
Post-Pliocene of Siberia (_Merycotherium_), although a true _Camelus_ of
large size appears to have inhabited some part of Central Asia in the Upper
Miocene period, being found in the Siwalik beds. The only exclusively
Pliocene genera in Europe are _Ursus_, _Equus_, _Hippopotamus_, _Bos_,
_Elephas_, _Arvicola_, _Trogontherium_, _Arctomys_, _Hystrix_ and _Lepus_;
but of these _Equus_, _Hippopotamus_, _Bos_, and _Elephas_ are found in the
Miocene deposits of India. Owing, no doubt, in part to the superior
productiveness of the various Miocene beds, large numbers of groups appear
to have their origin or earliest appearance here. Such are Insectivora,
Felidæ, Hyænidæ, Mustelidæ, _Ursus_, Equidæ, _Tapirus_, Rhinocerotidæ,
Hippopotamidæ, Anthracotheridæ (extinct), _Sus_, Camelopardidæ, Tragulidæ,
Cervidæ, Bovidæ, Elephantidæ, and Edentata.
Groups which go back to the Eocene period, are, Primates allied to South
American monkeys, as well as some of the Lemuridæ; bats of the living genus
_Vespertilio_; Hyænodontidæ, an ancestral form of Carnivore; Viverridæ;
Canidæ (to the Upper Eocene), and the ancestral Arctocyonidæ to the Lower
Eocene; _Hyænarctos_, an ancestral type of bears and hyænas; Anchitheridæ,
ancestral horses, to the Middle Eocene; Palæotheridæ, comprising numerous
generalised forms, ancestors of the rhinoceros, horse, and tapir; Suidæ,
with numerous generalised forms, to the Middle Eocene; Anoplotheridæ and
Xiphodontidæ, ancestral families of even-toed Ungulates, connecting the
ruminants with the swine; and lastly, several groups of Rodents, and a
Marsupial, in the Upper Eocene. We thus find all the great types of
Mammalia well developed in the earliest portion of the tertiary period; and
the occurrence of Quadrumana, of the highly specialized bats
(_Vespertilio_), of various forms of Carnivora, and of Ungulates, clearly
differentiated into the odd and even-toed series, associated with such
lower forms as {128}Lemurs and Marsupials--proves, that we have here hardly
made an approach towards the epoch when the mammalian type itself began to
diverge into its various modifications. Some of the Carnivora and Ungulates
do, indeed, exhibit a less specialised structure than later forms; yet so
far back as the Upper Miocene the most specialised of all carnivora, the
great sabre-toothed _Machairodus_, makes its appearance.
The Miocene is, for our special study, the most valuable and instructive of
the Tertiary periods, both on account of its superior richness, and because
we here meet with many types now confined to separate regions. Such facts
as the occurrence in Europe during this period of hippopotami, tapirs,
giraffes, Tragulidæ, Edentata, and Marsupials--will assist us in solving
many of the problems we shall meet with in reviewing the actual
distribution of living forms of those groups. Still more light will,
however, be thrown on the subject by the fossil forms of the American
continent, which we will now proceed to examine.
{129}CHAPTER VII.
EXTINCT MAMMALIA OF THE NEW WORLD.
The discoveries of very rich deposits of mammalian remains in various parts
of the United States have thrown great light on the relations of the faunas
of very distant regions. North America now makes a near approach to Europe
in the number and variety of its extinct mammalia, and in no part of the
world have such perfect specimens been discovered. In what are called the
"Mauvaises terres" of Nebraska (the dried-up mud of an ancient lake),
thousands of entire crania and some almost entire skeletons of ancient
animals have been found, their teeth absolutely perfect, and altogether
more resembling the preparations of the anatomist, than time-worn fossils
such as we are accustomed to see in the museums of Europe. Other deposits
have been discovered in Oregon, California, Virginia, South Carolina,
Texas, and Utah, ranging over all the Tertiary epochs, from Post-Pliocene
to Eocene, and furnishing a remarkable picture of the numerous strange
mammalia which inhabited the ancient North American continent.
NORTH AMERICA--POST-PLIOCENE PERIOD.
_Insectivora._--The only indications of this order yet discovered, consists
of a single tooth of some insectivorous animal found in Illinois, but which
cannot be referred to any known group.
_Carnivora._--These are fairly represented. Two species of _Felis_ as large
as a lion; the equally large extinct _Trucifelis_, found only in Texas;
four species of _Canis_, some of them larger {130}than wolves; two species
of _Galera_, a genus now confined to the Neotropical region; two bears, and
an extinct genus, _Arctodus_; an extinct species of racoon (_Procyon_), and
an allied extinct genus, _Myxophagus_--show, that at a very recent period
North America was better supplied with Carnivora than it is now. Remains of
the walrus (_Trichechus_) have also been found as far south as Virginia.
_Cetacea._--Three species of dolphins belonging to existing genera, have
been found in the Eastern States; and two species of _Manatus_, or sea-cow,
in Florida and South Carolina.
_Ungulata._--Six extinct horses (_Equus_), and one _Hipparion_; the living
South American tapir, and a larger extinct species; a _Dicotyles_, or
peccary, and an allied genus, _Platygonus_; a species of the South American
llamas (_Auchenia_), and one of a kind of camel, _Procamelus_; two extinct
bisons; a sheep, and two musk-sheep (_Ovibos_); with three living and one
extinct deer (_Cervus_), show an important increase in its Herbivora.
_Proboscidea._--Two elephants and two mastodons, added to this remarkable
assemblage of large vegetable-feeding quadrupeds.
_Rodentia._--These consist mainly of genera and species still living in
North America; the only important exceptions being a species of the South
American capybara (_Hydrochoerus_) in South Carolina; and _Praotherium_, an
extinct form of hare, found in a bone cave in Pennsylvania.
_Edentata._--Here we meet with a wonderful assemblage, of six species
belonging to four extinct genera, mostly of gigantic size. A species of
_Megatherium_, three of _Megalonyx_, and one of _Mylodon_--huge terrestrial
sloths as large as the rhinoceros or even as the largest elephants--ranged
over the Southern States to Pennsylvania, the latter (_Mylodon_) going as
far as the great lakes and Oregon. Another form, _Ereptodon_, has been
found in the Mississippi Valley.
_Marsupialia._--The living American genus of opossums, _Didelphys_, has
been found in deposits of this age in South Carolina.
_Remarks on the Post-Pliocene fauna of North America._--The assemblage of
animals proved, by these remains, to have {131}inhabited North America at a
comparatively recent epoch, is most remarkable. In Europe, we found a
striking change in the fauna at the same period; but that consisted almost
wholly in the presence of animals now inhabiting countries immediately to
the north or south. Here we have the appearance of two new assemblages of
animals, the one now confined to the Old World--horses, camels, and
elephants; the other exclusively of South American type--llamas, tapirs,
capybaras, _Galera_, and gigantic Edentata. The age of the various deposits
in which these remains are found is somewhat uncertain, and probably
extends over a considerable period of time, inclusive of the Glacial epoch,
and perhaps both anterior and subsequent to it. We have here, as in Europe,
the presence and apparent co-existence in the same area, of Arctic and
Southern forms--the walrus and the manatee--the musk-sheep and the gigantic
sloths. Unfortunately, as we shall see, the immediately preceding Pliocene
deposits of North America are rather poor in organic remains; yet it can
hardly be owing to the imperfection of the record of this period, that _not
one_ of the South American types above numerated occurs there, while a
considerable number of Old World forms are represented. Neither in the
preceding wonderfully rich Miocene or Eocene periods, does any _one_ of
these forms occur; or, with the exception of _Morotherium_, from Pliocene
deposits _west_ of the Rocky Mountains, any apparent ancestor of them! We
have here unmistakable evidence of an extensive immigration from South into
North America, not very long before the beginning of the Glacial epoch. It
was an immigration of types altogether new to the country, which spread
over all the southern and central portions of it, and established
themselves sufficiently to leave abundance of remains in the few detached
localities where they have been discovered. How such large yet defenceless
animals as tapirs and great terrestrial sloths, could have made their way
into a country abounding in large felines equal in size and destructiveness
to the lion and the tiger, with numerous wolves and bears of the largest
size, is a great mystery. But it is nevertheless certain that they did so;
and the fact that no such {132}migration had occurred for countless
preceding ages, proves that some great barrier to the entrance of
terrestrial mammalia which had previously existed, must for a time have
been removed. We must defer further discussion of this subject till we have
examined the relations of the existing faunas of North and South America.
TERTIARY PERIOD.
When we get to remains of the Tertiary age, especially those of the Miocene
and Eocene epochs, we meet with so many interesting and connected types,
and such curious relations with living forms in Europe, that it will be
clearer to trace the history of each order and family throughout the
Tertiary period, instead of considering each of the subdivisions of that
period separately.
It will be well however first to note the few American Post-Pliocene or
living genera that are found in the Pliocene beds. These consist of several
species of _Canis_, from the size of a fox to that of a large wolf; a
_Felis_ as large as a tiger; an Otter (_Lutra_); several species of
_Hipparion_; a peccary (_Dicotyles_); a deer (_Cervus_); several species of
_Procamelus_; a mastodon; an elephant; and a beaver (_Castor_). It thus
appears that out of nearly forty genera found in the Post-Pliocene
deposits, only ten are found in the preceding Pliocene period. About twelve
additional genera, however, appear there, as we shall see in going over the
various orders.
_Primates._--Among the vast number of extinct mammalia discovered in the
Tertiary deposits of North America, no example of this order had been
recognized up to 1872, when the discovery of more perfect remains showed,
that a number of small animals of obscure affinities from the Lower Eocene
of Wyoming, were really allied to the lemurs and perhaps also to the
marmosets, the lowest form of American monkeys, but having a larger number
of teeth than either. A number of other remains of small animals from the
same formation, previously supposed to be allied to the Ungulata, are now
shown to {133}belong to the Primates; so that no less than twelve genera of
these animals are recognized by Mr. Marsh, who classes them in two
families--Limnotheridæ, comprising the genera _Limnotherium_, (which had
larger canine teeth), _Thinolestes_, _Telmatolestes_, _Mesacodon_,
_Bathrodon_, and _Antiacodon_ of Marsh, with _Notharctos_, _Hipposyus_,
_Microsyops_, and _Palæacodon_ previously described by Leidy;--and
Lemuravidæ, consisting of the genera _Lemuravus_ (Marsh) and _Hyopsodus_
(Leidy). The animals of the latter family were most allied to existing
lemurs, but were a more generalized form, _Lemuravus_ having forty-four
teeth, the greatest number known in the order. These numerous forms ranged
from the size of a small squirrel to that of a racoon. It is especially
interesting to find these peculiar lemuroid forms in America, just when a
lemur has been discovered of about the same age in Europe; and as the
American forms are said to show an affinity with the South American
marmosets, while the European animal is most allied to a West African
group, we have evidently not yet got back far enough to find the primeval
or ancestral type from which all the Primates sprang.
About the same time, in the succeeding Miocene formation, true monkeys were
discovered. Mr. Marsh describes _Laopithecus_ as an animal nearly the size
of the largest South American monkeys, and allied both to the Cebidæ and
the Eocene Limnotheridæ. Mr. Cope has described _Menotherium_ from the
Miocene of Colorado, as a lemuroid animal, the size of a cat, and perhaps
allied to _Limnotherium_. More Miocene remains will, no doubt, be
discovered, by which we shall be enabled to trace the origin of some of the
existing forms of South American monkeys; and perhaps help to decide the
question (now in dispute among anatomists) whether the lemurs are really
Primates, or form an altogether distinct and isolated order of mammalia.
_Insectivora._--This order is represented by comparatively few forms in the
tertiary beds, and these are all very different from existing types. In the
Upper Miocene of Dakota are found remains indicating two extinct genera,
_Lepictis_ and _Ictops_. In the Miocene of Colorado, Professor Cope has
recently discovered four new genera, _Isacis_; allied to the preceding, but
as large as a {134}_Mephitis_ or skunk; _Herpetotherium_, near the moles;
_Embasis_, more allied to the shrews; and _Dommina_, of uncertain
affinities. Two others have been found in the Eocene of Wyoming; _Amomys_,
having some resemblance to hedgehogs and to the Eastern _Tupaia_; and
_Washakius_, of doubtful affinities.
Far back in the Triassic coal of North Carolina has been found the jaw of a
small mammal (_Dromotherium_), the teeth of which somewhat resemble those
of the Australian _Myrmecobius_, and may belong either to the Insectivora
or Marsupials; if indeed, at that early period these orders were
differentiated.
_Carnivora._--The most ancient forms of this order are some remains found
in the Middle Eocene of Wyoming, and others recently described by Professor
Cope (1875) from the Eocene of New Mexico, of perhaps earlier date. The
former consist of three genera, _Patriofelis_, _Uintacyon_, and
_Sinopa_,--animals of large size but which cannot be classed in any
existing family; and two others, _Mesonyx_ and _Synoplotherium_, believed
by Mr. Cope to be allied to _Hyænodon_. The latter consist of four
genera,-- _Oxyæna_, consisting of several species, some as large as a
jaguar, was allied to _Hyænodon_ and _Pterodon_; _Pachyæna_, allied to the
last; _Prototomus_, allied to _Amphicyon_ and the Viverridæ; and
_Limnocyon_, a civet-like carnivore with resemblances to the Canidæ.
In the Miocene formations we find the Feline type well developed. The
wonderful _Machairodus_, which in Europe lived down to Post-Pliocene times,
is found in the Upper Miocene of Dakota; and perfect crania have been
discovered, showing that the chin was lengthened downwards to receive and
protect the enormous canines. _Dinyctis_ was allied both to _Machairodus_
and to the weasels. Three new genera have been lately described by
Professor Cope from the Miocene of Colorado,--_Bunælurus_, with characters
of both cats and weasels; _Daptophilus_, allied to _Dinyctis_; and
_Hoplophoneus_, more allied to _Machairodus_. The Canidæ are represented by
_Amphicyon_, which occurs in deposits of the same age in Europe; and by
_Canis_, four species of which genus are recorded by Professor Cope from
the Miocene of Colorado, and it also occurs in the Pliocene. The _Hyænodon_
is represented by three species in the Miocene of Dakota and Colorado. It
occurs {135}also in the European Miocene and Upper Eocene formations, and
constitutes a distinct family Hyænodontidæ, allied, according to Dr. Leidy,
to wolves, cats, hyænas and weasels. The Ursidæ are represented by only one
species of an extinct genus, _Leptarchus_, from the Pliocene of Nebraska.
From the Pliocene of Colorado, Prof. Cope has recently described
_Tomarctos_, as a "short-faced type of dog;" well as species of _Canis_ and
_Martes_.
_Ungulata._--The animals belonging to this order being usually of large
size and accustomed to feed and travel in herds, are liable to wholesale
destruction by floods, bogs, precipices, drought or hunger. It is for these
reasons, probably, that their remains are almost always more numerous than
those of other orders of mammalia. In America they are especially abundant;
and the number of new and intermediate types about whose position there is
much difference of opinion among Palæontologists, renders it very difficult
to give a connected summary of them with any approach to systematic
accuracy.
Beginning with the Perissodactyla, or odd-toed ungulates, we find the
Equine animals remarkably numerous and interesting. The true horses of the
genus _Equus_, so abundant in the Post-Pliocene formations, are represented
in the Pliocene by several ancestral forms. The most nearly allied to
_Equus_ is _Pliohippus_, consisting of animals about the size of an ass,
with the lateral toes not externally developed, but with some differences
of dentition. Next come _Protohippus_ and _Hipparion_, in which the lateral
toes are developed but are small and functionless. Then we have the allied
genera, _Anchippus_, _Merychippus_, and _Hyohippus_, related to the
European _Hippotherium_, which were all still smaller animals,
_Protohippus_ being only 2½ feet high. In the older deposits we come to a
series of forms, still unmistakably equine, but with three or more toes
used for locomotion and with numerous differentiations in form,
proportions, and dentition. These constitute the family Anchitheridæ. In
the Miocene we have the genera _Anchitherium_ (found also in the European
Miocene), _Miohippus_ and _Mesohippus_, all with three toes on each foot,
and about the size of a sheep or large goat. In the Eocene of {136}Utah and
Wyoming, we get a step further back, several species having been discovered
about the size of a fox with four toes in front and three behind. These
form the genus _Orohippus_, and are the oldest ancestral horse known. Prof.
Marsh points out the remarkably perfect series of forms in America, which,
beginning with this minute ancient type, is gradually modified by gaining
increased size, increased speed by concentration of the limb-bones,
elongation of the head and neck, the canine teeth decreased in size, the
molars becoming longer and being coated with cement--till we at last come
to animals hardly distinguishable, specifically, from the living horse.
Allied to these, are a series of forms showing a transition to the tapirs,
and to the _Palæotherium_ of the European Eocene. In the Pliocene we have
_Parahippus_; in the Miocene _Lophiodon_, found in the same formation and
in the Eocene of Europe, and allied to the tapir; and in the Eocene,
_Palæosyops_, as large as a rhinoceros, which had large canines and was
allied to the tapir and _Palæotherium_; _Limnohyus_, forming the type of a
family Limnohyidæ, which included the last genus and some others mentioned
further on; and _Hyrachyus_, allied to _Lophiodon_, and to _Hyracodon_ an
extinct form of rhinoceros. Besides these we have _Lophiotherium_ (also
from the Eocene of Europe); _Diplacodon_ allied to _Limnohyus_, but with
affinities to modern Perissodactyla and nearly as large as a rhinoceros;
and _Colonoceras_, also belonging to the Limnohyidæ, an animal which was
the size of a sheep, and had divergent protuberances or horns on its nose.
A remarkable genus, _Bathmodon_, lately described by Professor Cope, and of
which five species have been found in the Eocene of New Mexico and Wyoming,
is believed to form the type of a new family, having some affinity to
_Palæosyops_ and to the extinct Brontotheridæ. It had large canine tusks
but no horns.
The Rhinocerotidæ are represented in America by the genus _Rhinoceros_ in
the Pliocene and Miocene, and by _Aceratherium_ and _Hyracodon_ in the
Miocene. Both the latter were hornless, and _Hyracodon_ was allied to the
Eocene _Hyrachyus_, one of the Lophiodontidæ. In the Eocene and Miocene
deposits of Utah, and Oregon, several remarkable extinct rhinoceroses have
been {137}recently discovered, forming the genus _Diceratherium_. These had
a pair of nasal horns placed side by side on the snout, not behind each
other as in existing two-horned rhinoceroses, the rest of their skeleton
resembling the hornless _Aceratherium_. They were of rather small size.
Next to these extinct rhinoceroses come the Brontotheridæ, an extraordinary
family of large mammalia, some of which exceeded in bulk the largest living
rhinoceros. They had four toes to the front and three to the hind feet,
with a pair of large divergent horns on the front of the head, in both
sexes. Professor Marsh and Dr. Leidy have described four genera,
_Brontotherium_, _Titanotheium_, _Megacerops_, and _Anisacodon_,
distinguished by peculiarities of dentition. Though most nearly allied to
the rhinoceroses, they show some affinity for the gigantic Dinocerata of
the Eocene to be noticed further on. Professor Cope has since described
another genus, _Symborodon_, from the Miocene of Colorado, with no less
than seven species, one nearly the size of an elephant. He thinks they had
a short tapir-like proboscis. The species differ greatly in the form of the
cranium and development of the horn-bearing processes.
We commence the Artiodactyla, or even-toed Ungulates, with the hog tribe.
These are represented by species of peccaries, (_Dicotyles_) from the
Pliocene of Nebraska and Oregon; and by an allied form _Thinohyus_, very
like _Dicotyles_, but having an additional premolar tooth and a much
smaller brain-cavity. From the Miocene are three allied genera, _Nanohyus_,
_Leptochoerus_, and _Perchoerus_. Professor Cope, however, thinks
_Leptochoerus_ may be Lemuroid, and allied to _Menotherium_. The
Anthracotheridæ, a family which connects the Hippopotamidæ and Ruminants,
and which occurs in the Miocene of Europe and India, are represented in
America by the genus _Hyopotamus_ from the Miocene of Dakota, and
_Elotherium_ from the Miocene of Oregon and the Eocene of Wyoming; the
latter genus being sometimes classed with the preceding family, and lately
placed by Professor Marsh, in the new order, Tillodontia. Professor Cope
has since described three other genera from the Eocene of New {138}Mexico:
_Meniscotherium_, having resemblances to _Palæosyops_, _Hyopotamus_, and
the Limnotheridæ; _Phenacodus_, the size of a hog, of doubtful position,
but perhaps near _Elotherium_; and _Achænodon_, as large as a cow, but more
hog-like than the preceding. Another new genus from the Miocene of
Colorado--_Pelonax_--is said by Professor Cope to come between _Elotherium_
and _Hippopotamus_.
The Camelidæ are very abundant, and form one of the most striking features
of the ancient fauna of America. _Procamelus_, _Homocamelus_, and
_Megalomeryx_, are extinct genera found in the Pliocene formation; the
first very closely allied to the Old World camel, the last smaller and more
sheep-like. In the Miocene two other genera occur, _Poebrotherium_ and
_Protomeryx_, the former allied to both the camel and the llama.
Deer are represented by a single species of _Cervus_ in the Pliocene, while
two extinct genera, _Leptomeryx_ and _Merycodus_, are found in the Miocene
deposits, the latter indicating a transition between camels and deer. Two
other genera, _Hypisodus_ and _Hypertragulus_, of very small size, are said
by Professor Cope to be allied to the Tragulidæ and to _Leptomeryx_.
The Bovidæ, or hollow-horned ruminants, are only represented in the Newer
Pliocene by a single species of an extinct genus, _Casoryx_, said to be
intermediate between antelopes and deer.
We now come to an exclusively American family, the _Oreodontidæ_, which
consisted of small animals termed by Dr. Leidy, "ruminating hogs," and
which had some general structural resemblances to deer and camels. They
abounded in North America during the Pliocene, and especially during the
Miocene epoch, no less than six genera and twenty species having been
discovered. _Merychus_ contains the Pliocene forms; while _Oreodon_,
_Eporeodon_, _Merychochoerus_, _Leptauchenia_, and _Agriochoerus_ are
Miocene. The last genus extends back into the Eocene period, and shows
affinity to the European Anoplotheridæ of the same epoch.
_Proboscidea._--The Elephantidæ are only represented in America by one
species of _Mastodon_ and one of _Elephas_, in the Newer Pliocene deposits.
In the Older Pliocene, Miocene, {139}and Upper Eocene, no remains of this
order have been found; and in 1869, Dr. Leidy remarked on the small average
size of the extinct North American mammalia, which were almost all smaller
than their living analogues. Since then, however, wonderful discoveries
have been made in deposits of Middle Eocene age in Wyoming and Colorado, of
a group of huge animals not only rivalling the elephants in size, but of so
remarkable and peculiar a structure as to require the formation of a new
order of mammals--Dinocerata--for their reception.
This order consists of animals with generalised Ungulate and Proboscidean
affinities. The lower jaw resembles that of the hippopotamus; they had five
toes on the anterior feet and four on the posterior; three pairs of horns,
the first pair on the top of the head, large and perhaps palmated, the
second pair above the eyes, while the third and smallest stood out sideways
on the snout. They had enormous upper canines, of which the roots entered
the middle horn cores, no upper incisors, and small molars. Professor Marsh
believes that they had no trunk. The remains discovered indicate four
genera, _Dinoceras_ (3 sp.), _Tinoceras_ (2 sp.), _Uintatherium_ (1 sp.),
and _Eobasileus_ (2 sp.). Many other names have been given to fragments of
these animals, and even those here given may not be all distinct.
Another new order, Tillodontia, recently established by Professor Marsh, is
perhaps yet more remarkable in a zoological point of view, since it
combines the characters of Carnivora, Ungulata, and Rodents. These animals
have been formed into two families, Tillotheridæ and Stylinodontidæ; and
three genera, _Tillotherium_, _Anchippodus_, and _Stylinodontia_. All are
from the Eocene of Wyoming and New Jersey. Perhaps to these must be added
_Elotherium_ from the Miocene of Dakota, the other forms being all Eocene.
They were mostly animals of small size, between that of the capybara and
tapir. The skull resembled in form that of a bear; the molar teeth were of
Ungulate type, and the incisors like those of a Rodent; but the skeleton
was more that of the Ursidæ, the feet being plantigrade. Professor Cope has
since described three new genera from the Eocene of New Mexico,
_Ectoganus_, _Calamodon_, and _Esthonyx_, comprising {140}seven species
allied to _Tillotherium_ and _Anchippodus_, and having also relations, as
Professor Cope believes, with the South American Toxodontidæ.