_Lepilemur_, Is. Geoffr., Cat. Méth. Primates, p. 75 (1851).
_Lepidolemur_, Peters, M. B. Akad. Berlin, 1874, p. 690 (1874).
This genus contains, according to Dr. Forsyth Major, as many as seven
species. This excellent comparative anatomist has made a very careful
revision of the group, and the present writer has gratefully to acknowledge
from him many valuable notes incorporated under this section, as well as
his kindness in supplying for publication the diagnoses of his new species.
Dr. Major divides these seven species into two series:--(A) a group of four
larger species, and (B) a group of three smaller species.
The members of this genus are smaller than the True Lemurs of the genus
_Lemur_. Their head is conical and short, their ears large, round, and
membranaceous, and the tail is shorter than the body. In this latter
character and in their shorter limbs they differ from _Mixocebus_. The
fourth finger and toe are the longest digits of their respective
extremities, the nails of all are keeled, and that of the great toe is very
large and flat.
{84}In the skull, the muzzle is longer than the longitudinal diameter of
its orbit in the series of larger species (Section A); in the smaller
species (Section B) the muzzle is shorter.
Their dentition presents several important characters. The series of upper
molars and pre-molars form almost a straight line, both sides being almost
parallel, or only slightly convergent towards the front. In the upper jaw
the incisors are wanting; the canines are very large and grooved
internally, and have a posterior heel. There is no gap between them and the
anterior pre-molar, which last is vertically taller than the rest, and has
one cusp to the outside, whereas the median and posterior have an inner
cusp as well. The anterior and median molars have the inner hind cusp
rudimentary, but the cingulum rises into a minute cusp, both at the fore
and hind edge; the posterior molar is three-cusped. The whole of the
cheek-teeth gradually broaden and decrease in vertical height from before
backward as far as the median molar. In the lower jaw the anterior
pre-molars are large, canine-like, and decumbent, and have a strong process
on their anterior margin (resembling that in the corresponding tooth in
_Indris_); the median and posterior pre-molars have one external cusp, and
the latter tooth one interior cusp in addition. The anterior and median
molars have a rudimentary fifth cusp, which is large in the posterior
molar.
The pre-maxillæ are very much reduced, so that the teeth they usually carry
are generally wanting. The bony palate is short, its hind margin extending
back only to the middle of the median molar; its anterior foramina are
small; and it differs from that of _Microcebus_ and _Chirogale_ in having
its posterior perforations small. The angle of the lower jaw is produced
downwards and backwards. The mastoid portion of the ear-capsules (periotic
bones) as well as the squamosal are markedly {85}enlarged and swollen, in
this respect differing from the skulls of _Lemur_ and _Hapalemur_. The
ridges in the temporal bone unite into a frontal (sagittal) ridge, and the
space between the orbits is depressed; a depression is also present on the
cheek in front of the lachrymal foramen. The foot is slightly elongated by
the lengthening of the _naviculare_ bone of the ankle (_tarsus_), the thin
bones of which are short. In the wrist (_carpus_) there is no _os centrale_
or central bone, which is otherwise invariably present in the Primates,
except in Man, the Chimpanzees, the Gentle-Lemurs, and the Endrina.
The Sportive-Lemurs are confined to Madagascar and are nocturnal and
arboreal creatures, feeding on leaves and fruits.
In Group A (the larger species) are included: 1, The Weasel-like Lemur (_L.
mustelinus_); 2, the Red-tailed Sportive-Lemur (_L. ruficaudatus_); 3,
Edwards' Sportive-Lemur (_L. edwardsi_); and 4, the Small-toothed
Sportive-Lemur (_L. microdon_). Group B (consisting of the smaller species)
comprises: 1, The Round-headed Sportive-Lemur (_L. globiceps_); 2,
Grandidier's Sportive-Lemur (_L. grandidieri_); and 3, the White-footed
Sportive-Lemur (_L. leucopus_). With the exception of the two first-named
species, all the others are here made known for the first time by Dr.
Forsyth Major. Very little is recorded of the habits of these animals. They
are so rare that at present the various species are known from a few skins
or alcoholic specimens in European museums. They are said to be inhabitants
only of the forest-country, nocturnal in their habits, sleeping coiled up
in some retreat all day, but issuing forth at night, at which time they are
very agile in their movements.
{86}SECTION A. (SPECIES MAJORES.)