The scallop-shells (/Pecten/) are objects too familiar to require

any general description. The rounded valve, usually ornamented with

radiating ribs, and the wing-like projections (called "ears"), from

each side of the umbonal region, are never-failing characters. The

outline of /Pecten/ has been considerably employed in conventional

designs for mural decorations; indeed, the figure [pg436] of a

well-known Mediterranean pecten (/P. jacobius/), found commonly

in Palestine, became an emblem of religious significance during

the middle ages. Returning crusaders fastened to their garments a

specimen of "St. James's shell" as an evidence of the fact that they

had been to the Holy Land, and the design of the shell came to be

adopted upon many coats of arms and also in the insignia of various

orders of devout and adventurous knights of the middle ages.

The animal is of the highest type of monomyarian mollusks, that is,

of bivalve mollusks with only a single adductor muscle. Unlike most

pelecypods, which have a very small foot, /Pecten/ rarely has a

byssus, and is neither a stationary nor a sluggish creature. It can

propel itself through the water by spasmodically closing and opening

its valves, in an eccentric, darting sort of flight, though most of

the time it rests quietly upon the bottom. The mantle is entirely

open and highly ornate about its margin, which is, furthermore, the

seat of many eyes, capable, apparently, of no mean degree of vision.

The adductor muscle is very large and strong, and occupies a central

position, about which the gills circle; the latter are plainly

filamentous.

^P. magellanicus.^ The largest of the east-coast species of

/Pecten/. It is a Northern species, and was long known by the

name of ^P. tenuiscostatus^--a name given to it on account of

its very numerous radiating striæ; but it was later discovered

that the North Atlantic form was in reality the same as the /P.

magellanicus/ of Patagonia. The latter being the older name and

entitled to priority, our shell became /P. magellanicus/, the

other name falling within its synonymy. The length and height of

this scallop are from five to five and a half inches. One valve

is more convex and slightly larger than the other, the smaller

being lighter in color. The valves gape considerably along their

upper margin below the hinge. The cartilage-pit is deep. North of

Cape Ann this large species is of common occurrence in moderately

deep water. The deeper bays and arms of the sea which everywhere

penetrate the Maine coast are its favorite resorts. A good way

to catch pectens is to lower a fishing-line at a spot where the

fishermen report "scallop-ground," and drag it along over the

bottom. Sooner or later it will enter the open shell of some

pecten, which will instantly close its valves upon the string and

allow itself to be drawn out of the water. In Maine these large

scallops are eaten, but they have not found great favor in the city

markets. In color they vary from reddish through brown to ashen.

^P. islandicus.^ A species not so large as the last, with more

prominently raised ribs (about fifty to one hundred in number),

which are [pg437] covered with a multitude of erect scales. The

ribs persist upon the interior of the shell. The "ears" are unequal

in size. The color is light orange to reddish-brown, with zones of

darker and richer color. One valve is flatter than the other and

more lightly colored. Greatest length about three inches; height

three and a half inches. This is a Northern shell, belonging to the

waters of Newfoundland, but its valves are frequently cast upon the

New England beaches.

[Illustration: /Pecten islandicus./]

^P. irradians.^ The common shallow-water species of the Atlantic

coast. This exceedingly abundant species does not range north of

Boston, but finds an extensive habitat to the south. Its metropolis

is Cape Cod, Long Island Sound, and the Jersey coast waters. This

is the true scallop of the Boston and New York markets. Only the

adductor muscle is eaten. In this species there is not so marked

a difference in the convexity of the two valves. There are about

twenty elevated and rounded ribs, the spaces between them being

also rounded. The color is variable, from a blackish horn to ashen

gray. The "ears" are equal; the interior is shining, and grooved

to correspond with the external ribs. Length two and three fifths

inches, height two and a half inches. On clear, calm days the

immature individuals of this species may often be seen in shallow

water disporting themselves most gaily, skipping about and snapping

their valves in great glee. Their mantle margins are very ornate

in scarlet or orange, with rows of bright-blue eyes. Care must be

taken in handling scallops, especially the large /P. magellanicus/,

for a finger caught between the valves will be badly bruised.

^P. dislocatus.^ South of Hatteras this species takes the place of

its Northern relative, /P. irradians/. It is somewhat more globular

and perhaps not quite so large, but the resemblance between the two

species is very marked. It has from twenty to twenty-two rounded

ribs, with very numerous concentric wrinkles between them. In

color it is white, tinged with purple or yellow, with occasionally

a system of blood-red lines crossing the ribs transversely. The

diameter is about one and a half inches. This species has the

same playful habits as /P. irradians/, and is not at all easy to

capture. When pursued it dives into the mud, and sets up such a

commotion by the spasmodic opening and shutting of its valves that

the water at once becomes roiled, and the scallop is safely hidden

in its murky depths. [pg438]

^P. hastatus.^ There are several very beautiful pectens on the

Pacific coast of the United States, and two of these--one of

northern and the other of southern range--resemble very closely

the two Atlantic species of relatively north and south range, /P.

islandicus/ and /P. irradians/ or /dislocatus/. The first is /P.

hastatus/ of Puget Sound. Valves of this exquisite shell are even

occasionally found in California. It has very much the aspect of

/P. islandicus/--unequal ears and an ovate form. The most curious

thing about this shell is the fact that a different system of

sculpturing exists upon the two valves. Upon one the ribs are even

and the whole surface is covered with raised scales; upon the other

the ribs are alternately of large and small size. Color rose-pink,

with deeper bands; one valve lighter-colored, suffused with

delicate pink. Height two and a half inches. (Plate LXXIX.)

[Illustration: /Pecten irradians/, typical form.]

^P. æquisulcatus.^ The Southern species above referred to as

resembling /P. irradians/ or /dislocatus/. It has about twenty

stout, well-rounded ribs, with concentric wrinkles between

them. The "ears" are equal. The size and shape are as in /P.

irradians/. The coloring is whitish, varying to shades of brown,

and excentrically marked with spots or waving transverse lines of

chestnut or horn.

ORDER =EULAMELLIBRANCHIATA=

With the pectens we leave behind all pelecypods with the true

filamentous type of gill. In the order /Eulamellibranchiata/ we find

all the families to be possessed of the basketwork or crisscross

branchial structure. Each gill is fundamentally formed of filaments

which project downward, and then suddenly turn upon themselves and

ascend; the ascending and descending limbs are connected, however, by

processes of presumably vascular function, and adjacent filaments are

connected by truly vascular channels. The closer connection of the

filaments to form of each gill a sort of plate is further effected

[pg439] by connective tissue, which sometimes is dense enough (though

always porous) to obscure the reticulated appearance of the organ.

Furthermore, the edge of the outer lamella of the outer gill unites

with the mantle; likewise the edge of the inner lamella of the inner

gill unites with the body-mass, and /behind the body-mass/ with the

gills upon the other side of the animal. This union of the four gills

in a straight median line behind the foot and body-mass forms a

septum, which divides off from the mantle cavity a "suprabranchial"

cavity. Into this cavity the excreta are discharged, and with it the

anal or excurrent siphon connects. The branchial or incurrent siphon

thus pours its current of water into the /lower/ mantle cavity, to

bathe the gills and feed the mouth, while the fresh water is not

contaminated by any open and wide connection with the excretory

processes. In many of the forms where the siphons are very long and

united, this septum, formed by the union of the dorsal edges of the

inner gills back of the foot, is continued far into the siphons,

constituting the division of the two into the anal and branchial

siphons.

Another feature of this order is the marked tendency to mantle

fusion. As there are always siphons, the mantle-edges must

necessarily have fused at two points at least, in order to have

formed the siphons. The tendency, however, is for the fusion to

continue, narrowing the pedal opening more and more, as though the

mantle were endeavoring to envelop the entire animal in a bag or sac

open only at one end (siphonal opening), but yet slightly ripped

along one seam (pedal opening).

This order includes the great majority of pelecypods, and admits of

many very confusing modifications in its most essential features.

FAMILY ~CARDITIDÆ~

In this, the first family of the order, most of the characteristic

features just spoken of are present. Mantle fusion, however, has

not progressed beyond a degree which is just sufficient to form the

siphons. There is a byssiferous gland. The name /Carditidæ/ refers to

the heart-shape of the shells. [pg440]

GENUS ^Cardita^

[Illustration: /Cardita borealis/, natural size.]

^C. borealis.^ A very common species north of Cape Ann, reported

also in deeper water as far south as Hatteras. It is a solid,

obliquely heart-shaped shell, with beaks elevated and turned

forward. It has about eighteen to twenty rounded radiating ribs,

which are broader than the grooves between them. The epidermis

is rusty-brown. The hinge is strong, with two prominent teeth;

the margins of the shell are strongly crenulated within.

Length one inch; height about the same. This is not strictly a

between-the-tides species, but its valves are often cast upon the

beaches. Fine specimens may be obtained by dredging at Bar Harbor

or Eastport.

^C. floridana.^ A very common Floridian species. Its seventeen or

eighteen ribs are very heavy, and are rendered nodulous by the

numerous bluntly raised scales upon them. The shell is lengthened,

and has a well-defined lunule and an external ligament. In color

it is yellowish-white, with purple markings when young. Length one

inch; height three fourths of an inch. It lives in sheltered bays;

detached valves are often found cast upon the beach.

FAMILY ~ASTARTIDÆ~

GENUS ^Astarte^

Notwithstanding their rather small size, there is a trimness about

the shells of /Astarte/ which, taken together with their rich

chestnut epidermis, makes them very interesting and desirable

additions to the cabinet. The family is one of cold-water range, with

a few representatives on the New England coast. Live specimens are

not easily captured, for they live in deeper water than one would

care to wade in, nevertheless they are frequently cast upon the

beaches after storms. The animal has a very short efferent siphon,

large labial palps, and very obliquely placed gills. Not more than

twenty living species of /Astarte/ are known, and all of them belong

in, or are wanderers from, polar seas. Fully three hundred fossil

species of this genus have been described from Mesozoic rocks in all

parts of the world. The question naturally arises whether in these

its dying days /Astarte/ has sought colder waters in which to pass

its remaining existence, or whether climates have changed. The fact

that such strictly [pg441] tropical genera as /Voluta/ and /Conus/

are found fossil in northern Siberia seems to be evidence in proof of

great climatic variations.

^A. castanea.^ This species has a thick and heavy shell for one

so small, with round ventral margins and prominent beaks. The

surface is very slightly undulated and is covered with a thick

chestnut epidermis with pale and dark zones. The hinge is broad and

flat, with a prominent cardinal tooth upon the right valve, which

accurately fits into a pit formed by two teeth on the left valve.

Length one inch; height one inch.

[Illustration: /Astarte castanea./]

^A. undata.^ A species slightly larger than the last, with ten to

twenty prominent concentric undulations.

[Illustration: /Astarte undata./]

The identification of the many species of /Astarte/ often becomes

exceedingly difficult on account of the fact that the genus is a

remarkably uniform one in its main characters and is infinitely

variable in its minor details.

FAMILY ~CYPRINIDÆ~

GENUS ^Arctica^

This family is represented by one species upon the New England coast,

which is much sought after by collectors. It is one of the larger

clams, but is too uncommon to have received a popular name and to be

generally well known by the fishermen along the shore.

[Illustration: /Arctica/ (/Cyprina/) /islandica/.]

^A.^ (^Cyprina^) ^islandica^. This clam has a thick though not

ponderous shell, with prominent beaks and a stout, prominent

ligament. Its cardinal teeth are large, but its laterals are very

small. A striking feature of this species, which at once separates

[pg442] it from all other shells of our coast of similar size,

is the coarse, wrinkled epidermis of black to chestnut color.

The shell is very suggestive of a large, overgrown /Astarte/.

Length three and a half inches; height three inches. It is found

of all sizes, down to one fourth of an inch in diameter, upon

muddy stations in moderately deep water near the mouths of rivers;

but the surest way to get it is to search the beach after a hard

onshore gale.

FAMILY ~LUCINIDÆ~

This family finds its metropolis in warmer waters, and the best

representatives of it must be sought for upon the Floridian beaches

or in the shallow bays of that sandy coast. A long vermiform foot

is a characteristic of the animal, as is also the fact that at

times there is only a single gill upon each side of the body. In

some of the /Lucinidæ/, more so than in most other pelecypods, the

chief function of the gills is to furnish a brooding-place for the

thousands of ova which the creatures generate. Sometimes a /Lucina/

will be captured with the gills swollen out of all proportion,

and literally stuffed with tiny, microscopic eggs. At such times

the gills lose all semblance of branchial organs. The shells are

orbicular, with depressed small umbones, a distinct lunule, a

semi-external ligament, two cardinal teeth, and laterals (a variable

feature). There is no pallial sinus. The color is white, and the

outlines are rounded.

GENUS ^Lucina^

^L. tigrina.^ The largest of the group, measuring three inches

across and nearly the same in height. It is flatly convex and

radially ribbed by a great number of costæ which are crossed and

decussated throughout with concentric ridges. The color is white.

This fine shell lives only in southern Florida and is abundant in

shallow water on sandy stations. (Plate LXXX.)

^L. floridana.^ One of the most abundant bivalves in Florida, often

cast in thousands upon the beaches. It lives in shallow protected

waters and upon sand-flats which are partly exposed at low tide.

It has the usual round outlines of the genus, with exceedingly

small umbones, directed forward, and a smooth surface, save for

fine growth-lines of a light straw-color. The shell is pure white.

Diameter about one inch. (Plate LXXX.)

^L. pennsylvanica.^ A species often associated with the last,

but about twice as large. Its thin but tough epidermis clings

to the shell in raised concentric lines, giving it a circularly

ribbed appearance. The most prominent feature of this species is

a depressed line upon either valve extending obliquely from the

umbones to the posterior ventral margin, [pg443] causing, at the

margin, a pucker or break in its even continuity. The lunule is

large and ribbed; the teeth are small; the color is pure white,

with a light straw-tinted epidermis. (Plate LXXX.)

^L. dentata.^ In this species the shells are thin and white, with

well-marked concentric lines crossed by deep oblique narrow furrows

bent at nearly right angles to the lines of growth and forming

teeth around the margin. Found along the entire coast.

[Illustration: /Lucina dentata./]

^L. californica.^ The best-known California species of this genus.

It is pure white, with fine concentric lines, and varies in size

from one half of an inch to one and a half inches in diameter. The

lateral teeth are the stronger, and the lunule is upon the right

valve only. With these exceptions this species preserves the usual

characters of this genus.

^L. nuttallii^, belonging to the southern shores of California, is

decussated like fine wickerwork. The shell is flattened and ridged

along the hinge-margin. The color is white. Diameter about one inch

in large specimens. (Plate LXXX.)

GENUS ^Loripes^

^L. edentula.^ A species which is seldom captured alive. Its

home is in the open sea, but vast quantities of its valves are

occasionally thrown upon the beaches south of Hatteras, as far as

the Gulf of Mexico. On account of the weak hinge ligament, the

valves become easily separated, and it is not always easy to find

two that will exactly match. /Loripes/ preserves the same circular

outlines as /Lucina/, but is more ventricose, and the hinge and

teeth are very feeble. This species is a little over two inches in

length and slightly under two inches in height. It is pure white

without, and is finely striated with growth-lines; bright orange

within, especially about the pallial line and muscle-scars. (Plate

LXXX.)

FAMILY ~TELLINIDÆ~

GENUS ^Tellina^

If we should create an aristocracy of beauty among the bivalves, as

has been done by conchologists among the gasteropods, this family

would deserve high rank. Most of the American species of /Tellina/

are too small to impress one very greatly with their beauty, but

in the West Indies and in the tropical Pacific waters are some

wonderfully handsome shells belonging to this or to the allied genus

/Macoma/. However, we have in Florida the very striking /T. radiata/,

a truly beautiful shell, which, were it less common, would be highly

prized in collections. Rarity, no doubt, adds a wonderful luster

to shells as well as to gems. The [pg444] animal of /Tellina/ has

long, slender siphons, which are separate. The gills are small, and

the outer lamella or branchial fold is directed dorsally. Although

the foot shows evidences of a byssogenous gland, there is no actual

byssus. The shells are porcelanous and translucent, equivalve, with

an external ligament, and at least two cardinal teeth in each valve.

^T. radiata.^ This species varies from three to four inches in

length, and from one and a half to one and three fourths inches

in height. It is highly polished, shining white, and yellowish

about the umbonal region, and has three wide rays of bright pink

extending from the beaks to the ventral margin. On account of its

remarkable coloration it is called the "setting-sun shell." Its

surface is smooth. A common variety is of a uniform creamy-white

color with carnation beaks. This shell is always offered for sale

by the marine curio- and shell-dealers in Florida seaside resorts,

and at Atlantic City, Cape May, and elsewhere.

^T. alternata^ resembles the last in shape, being flattish and

oblong, but it is more pointed or angulated posteriorly. There is

also a slight twist in the posterior end of the shell. Its surface

is decorated by numerous impressed concentric lines. The color is

uniformly white or yellowish, with pink rays. Length two and a half

to three inches; height two and a half inches. Found from Hatteras

to the Gulf of Mexico, in shallow, sandy stations and on beaches

after storms. (Plate LXXXI.)

^T. bodegensis.^ The most striking species of /Tellina/ found on

the west coast, and of rather northern range. It is about two

inches in length, creamy-white in color, and ornamented with very

fine concentric lines. A very characteristic feature of the genus

is present in this species as in the last, namely, a slight twist

or bend to one side in the posterior end of the shell.

[Illustration: /Tellina tenera/, showing extended animal.]

[Illustration: /Tellina tenera./]

^T. tenera.^ A little /Tellina/ found in New England waters, which,

though very small, is worthy of mention on account of its abundance

upon all our beaches north of Hatteras. It is only about half an

inch long, and slightly over one quarter of an inch high. It may

be distinguished by its general generic characters, its iridescent

surface, and its delicately marked lines of growth; sometimes

it is rose-tinted. Its remarkably long siphons are shown in the

accompanying figure.

GENUS ^Macoma^

^M. secta.^ A very pretty thin glossy shell from two to three

inches in length and about one fourth less in height, which

occurs from Monterey southward. The posterior end of the shell is

contracted and slightly bent; the pallial sinus is deep. There is

an external ligament. (Plate LXXXI.)

[Illustration: PLATE LXXX. 1, Lucina tigrina. 3, Lucina

pennsylvanica. 2, Lucina floridana. 4, Lucina nuttallii. 5, Loripes

edentula.]

[Illustration: PLATE LXXXI. 1, Tellina alternata. 3, Donax

variabilis. 2, Macoma secta. 4, Donax californicus. 5, Ræta

canaliculata.]

^M. nasuta.^ Another Californian species, with a less shining

surface and a very thin light-brownish epidermis. The twisting of

the posterior [pg445] margin is striking. It has very fine

cardinal teeth. Length two to three inches.

^M. baltica^, ^M. proximo^, ^M. tenta^. The first two of these

species are dingy in color, and are covered with a dirty-looking,

thin epidermis. The first has a wide range to Norway and Scotland,

and is exceedingly common all along our coast from Maine to

Georgia. It occurs plentifully in the Hudson River above New York,

and in all sandy or muddy bays. It is rounded in outline, while the

next species (/M. proxima/) is more pointed posteriorly. When these

species are buried in the sand their two long, slender siphons

project above, one supplying the animal with a constant current

of fresh water, and the other ejecting that which, having passed

the gills and labial palps, is exhausted of its air and nutriment

and contaminated by waste products. /M. tenta/ is white, with very

fine lines of growth, and polished and shining within. It is warped

posteriorly. Length three fifths of an inch; height two fifths of

an inch.

[Illustration: /Macoma baltica./]

[Illustration: /Macoma tenta./]

FAMILY ~DONACIDÆ~

GENUS ^Donax^

The /Donacidæ/ are represented upon our coasts by comparatively

few species, all belonging to the genus /Donax/. The shells are

under an inch in length, and have a peculiarly shortened anterior

portion; thus they are inequilateral. Their ventral margins are

finely denticulate. The pallial sinus is deep. There are two or three

cardinal teeth and a variable number of laterals.

^D. variabilis.^ This little shell, the common Floridian form,

exhibits every imaginable scheme of color-combination, and defies

general or comprehensive description. Probably the most usual

pattern developed is a bluish-white background with purplish

radiating lines. Another is a pure-white foundation with red

lines. The surface is striated longitudinally with excessively

fine riblets. Length one half of an inch or slightly more. In

March and April these shells are thrown alive in millions upon the

Florida beaches. Each wave seems to be laden with them, and when

the foaming waters of each spent breaker recede, the little shells

lie still upon the sand for a moment, glittering like jewels in the

sunlight; then, with a sudden protrusion of the foot and a quick

turn, they all disappear like a flash, buried in the sand before

the next breaker strikes them. One must be very quick to catch

these active little mollusks. (Plate LXXXI.)

^D. californicus.^ Professor Keep very aptly describes this shell,

which is very common in California, as "short and stumpy, cut

nearly square off at one end (anterior), and tapering to a rounded

edge at the other." The same description fits both this and the

Floridian /D. variabilis/ so well that the two forms may be one

and the same species. [pg446] If they were shells of arctic

range it would be easier to connect them; but as neither is a

cold-water form, it becomes more difficult to place them under one

name. The increasing number of similar species being found upon

the Atlantic and Pacific sides of Central America points almost

conclusively to the existence of a waterway between the two oceans,

somewhere between North and South America, at no very remote

geological period. Possibly the closing of some such waterway

through the isthmus connecting the oceans has separated these forms

geographically, thus leading us to separate them specifically.

(Plate LXXXI.)

FAMILY ~MACTRIDÆ~

This is a very large family of universal distribution and with a

great number of genera and subgenera, rather confusedly gathered

into subfamilies. The dominant genus /Mactra/ comprises the largest

bivalve upon the east coast of the United States.

GENUS ^Mactra^

The mactras live in the sand near the margin of the water, often

upon the exposed open coast. The mantle is open, except where it is

fused to form the siphons. These are short and united. The outer gill

is dorsally directed; that is to say, it does not depend into the

mantle cavity as does the inner gill, but projects just the other

way; it is also smaller than the inner one. The foot is strong,

bent, and tongue-shaped, and no doubt well adapted to the rough life

in the surf and the heavy, shifting sands. The main characteristic

of the mactra shell is the prominent triangular-shaped fossette,

or cartilage plate, situated internally and just under the beaks.

The shells are equivalve, and devoid of bright colors or striking

sculptural features. Internally the pallial line is plain, and the

sinus well marked but not deep.

[Illustration: /Mactra solidissima./]

^M. solidissima^ is one of the very commonest, if not the

commonest large bivalve of the New England, Long Island, and New

Jersey [pg447] beaches. It is covered with a thin brownish or

straw-colored epidermis, usually more or less worn away in adult

specimens and wholly absent from the dead valves found upon the

beaches. There is a fragile V-shaped cardinal tooth, which is

generally broken away in forcing open the valves; the lateral teeth

are long and thin, and striated on their receiving surfaces. The

length of this "giant clam" is from four to seven inches. This is

the first shell the collector will find (north of Hatteras) when he

goes to an open, sandy beach.

^M. similis.^ A small variety of the species last described, of

similar outline, but less heavy and strong. Its range is from

Hatteras southward to Brazil. Passing from New Jersey to Hatteras,

/Mactra solidissima/ diminishes in size, and after passing that

faunal barrier the Northern form is entirely replaced by this

Southern variety. The shell is brighter, though not exactly

bright-shining. Its habits are entirely similar to those of the

Northern form. On the west coast of Florida it is the most abundant

bivalve upon the beaches.

^M. ovalis.^ A species of Northern range, which so greatly

resembles /M. solidissima/ as to suggest identity; but the lateral

teeth are smooth and not striated, while the shell itself seldom

attains a length of over four inches.

^M. lateralis.^ An exceedingly common shell, found in all the

salt-marshes and tidal estuaries of our coast. It is much smaller

than the mactras just described, being not over one half of an

inch in length. It is white, and is covered with a dirty brown

epidermis; the hinge is strong, with deep cartilage fossette and

a V-shaped marginal tooth. The laterals are long and slender. The

animal has a strong foot and two slender, long siphons which are

yellow in color.

[Illustration: /Mactra lateralis./]

GENUS ^Ræta^

^R. (Labiosa) canaliculata.^ In this species the cartilage fossette

is the same as in /Mactra/; the marginal teeth are feeble, and

there are no laterals. The shells of /Mactra/ which we have

examined are heavy or at least solid, but /Ræta/ is thin and

fragile; it is pure white in color and is gracefully ornamented by

concentric raised ribs. The shell is inflated and gapes slightly

posteriorly; it is shining white within and is deeply grooved

concentrically in accordance with the external ribs. Length two

and a half, height two inches. From Hatteras to Mexico, this is

one of the commoner beach shells, but since, as in some other

species already named, the hinge ligament and teeth are feeble, the

valves become separated by the buffeting of the waves, and are cast

disjointed and singly upon the beaches. (Plate LXXXI.)

FAMILY ~VENERIDÆ~

In many respects this is the most distinguished pelecypod family.

It is the largest in number of genera and species, is of world-wide

distribution, and supplies to hungry man a number [pg448] of

comestible species. Several of its genera have been named after

various goddesses and nymphs on account of the great beauty of

their shells. But from a purely biological point of view also the

/Veneridæ/ have claims to distinction, for they seem to represent

about the highest type of shell-development among the bivalves. The

test is extremely hard and often porcelanous. It is solid without

being ponderous and unwieldy in the sense of causing the animal to

be helplessly overburdened by the sheer weight of its shell. The

valves are equal and have three stout cardinal teeth. The foot is

strong, the animal is active, the siphons are free or partially

united, and the gills are more or less crumpled and folded. There is

a compactness and well-regulated arrangement of the organs in the

/Veneridæ/, which impress one who has examined the anatomy of many

pelecypods much as a well-built, efficient, and space-economizing

machine would impress a mechanic. None of the organs are weak or

crowded out to furnish room for the undue or awkward development

of other organs. A good balance is preserved between them all, the

result being a high type of pelecypod.

If we do not expect to find any of the more remarkable forms of the

/Veneridæ/ upon our shores we shall be the less disappointed when

returning from collecting-expeditions. Nevertheless, there are a few

species of /Cytherea/, /Dosinia/, and /Tivela/ in North American

waters which are very handsome shells; but those of our species which

are included under the generic name /Venus/ are in point of beauty

not worthy of their promising name.

GENUS ^Venus^

^V. mercenaria.^ This is the common "hard-shell clam," the "Little

Neck" of the hotels and restaurants, with which every one in New

York and New England is familiar. The species ranges from Cape

Cod to Florida, and occupies two different kinds of station: one

in shallow muddy bays near low-tide mark, in estuaries, etc.; the

other the sandy stations in open deeper bays or the open ocean.

Those coming from "outside" have thinner, more delicate shells,

with thin, concentric ribs. They burrow in the sand or mud, or

crawl quite rapidly. The siphons are short and are united almost

to their ends. The mantle is open (save for the siphons), and the

edges are delicately frilled. In the United States this species

is very extensively gathered for the markets. When the oyster

season closes in April, the hard-shell clam comes into vogue, the

season lasting until September or October. The clams are [pg449]

extensively gathered in the estuaries from Cape May to Cape Cod.

Men armed with rakes drift about in small boats and fish the

sluggish creatures up out of the mud. They will live for many days

out of water if kept in a cool place. Smaller or immature clams are

better for the table, since they are not so tough as their elders.

A few features of the shell of this species are noticeable--the

rather prominent umbones directed forward, the heart-shaped lunule,

the external ligament, the concentric sculpturing of growth-lines,

the pure-white interior (with occasionally violet zones about

the muscle-scars and margin), the three stout cardinal teeth,

the sharp-angled pallial sinus, and the ventral margin finely

crenulated within. The greatest length is about three inches and

the height two and a half inches, but these dimensions exceed those

of the clams usually served upon the half-shell. /V. mercenaria/

ranges into Florida, increasing in size and bulk as it meets the

warmer waters of the Gulf Stream. The Floridian form has received

the varietal name of /mortoni/. This massive clam sometimes weighs

five pounds, and is fully six inches in diameter. Aside from its

great size and thickness, the characters of the shell are wholly

those of the smaller Northern form. It is abundant in shallow,

muddy, brackish bays, and is gathered by men who "tread out" the

clams, feeling for them in the mud and sand with bare feet. The

flesh is tough and disagreeably strong, yet the natives appear to

relish it, especially when it is made into a chowder.

[Illustration: /Venus mercenaria/, typical form.]

^V. cancellata.^ The most abundant species of /Venus/ in Florida,

particularly near Tampa and on the west side. It preserves all the

characteristics of the genus, and is decorated with a series of

high, narrow, concentric ridges, between which are much smaller and

more numerous radiating riblets. The color is dirty white to light

yellow-brown without, and white and violet within. There are three

cardinal teeth and no laterals. The lunule is heart-shaped; the

posterior margin is broadened into a wide, concave area into which

the concentric ridges do not pass. Length one to one and a fourth

inches; height the same. Sometimes the beaches in Florida will in

places be banked up with the valves of this very abundant /Venus/.

As they live in shallow water upon sandy stations, they are easily

dislodged by the heavy storms which sometimes sweep that usually

placid coast. (Plate LXXXII.) [pg450]

GENUS ^Cytherea^

^C. (Callista) gigantea.^ One of the most beautiful Floridian

shells. It is nearly or quite six inches long and about three and

a fourth inches in height. The shell is porcelanous, is covered

with a pinkish, livid epidermis, and is decorated with numerous

longitudinal color-rays of lilac. The rays are usually broken and

interrupted. Within it is china-white, and has a deep pallial

sinus. It is very abundant on the west coast of Florida, at Sanibel

Island, Egmont Key, Lake Worth, and on beaches. (Plate LXXXII.)

^C. maculata.^ This species is more oval in outline than the last.

It is of a fawn-color, blotched or waved with violet-brown, and

is porcelanous and shining. The epidermis is also shining and

corneous. Within it is china-white in color. The pallial sinus is

very deep and wide. Length two and a half to three inches; height

one and a half to two inches. This also is a shell to be looked for

upon the beach after storms, but it will probably not be seen on

the east coast of Florida, although it occurs on the Keys and also

at Hatteras. Both of the species have been used as food, but not

very extensively. The flesh is not lacking in tenderness, but it

has a peppery taste. (Plate LXXXII.)

GENUS ^Dosinia^

There are two species of this very graceful genus of /Veneridæ/

south of Hatteras, ^D. discus^ and ^D. elegans^. These dosinias

have united siphons. The foot is very large and strong, and the

mantle margin is both papillaceous and plicated. The shells of

these two species are about three or three and a half inches in

length and of the same height, and are very flat. The ventral

margin is almost a perfect circle, and the beaks are small and

pointed. The lunule is small and cordate; the valves are very

gracefully sculptured in fine, regular, impressed, concentric

striæ, which are finer and less elevated in /D. discus/ than in

/D. elegans/; the shell is porcelanous and white, and is covered

by a straw-colored, very fine, transparent epidermis. Within, the

strong cardinal teeth are placed upon a long fossette. There is a

deep pallial sinus. /D. discus/ is characteristic of the east coast

of Florida, while /D. elegans/ is only found upon the west side of

the State. Both may be looked for upon the beach, though living

specimens must be captured with the dredge. (Plate LXXXII.)

[Illustration: PLATE LXXXII. Venus cancellata. /Cytherea/

(/Callista/) /maculata/. /Cytherea/ (/Callista/) /gigantea/. Dosinia

discus.]

GENUS ^Tivela^

The coast of California is also favored by the /Veneridæ/, a number

of large species belonging to several genera being present.

[Illustration: PLATE LXXXIII. Tivela crassatelloides, one half

natural size. Chione succincta. Tapes laciniata, one half natural

size. Chione simillima.]

^T. crassatelloides.^ Perhaps the largest and finest of the

California species. It is so common in its between-tides station

that it used to be collected by plowing a furrow through the

sand, the big shells being thrown out upon either side like

potatoes. The shells attain a length of five and a half inches,

and are porcelanous, thick, and heavy. The margins of the valves

are also thick and rounded. The exterior is perfectly smooth,

yellowish-white in color, and decorated [pg451] with purplish

rays arranged in various groupings; over all is a glossy epidermis.

The hinge-teeth are very strong, and a prominent anterior lateral

tooth on the left valve is noticeable. There is an external

ligament; the pallial sinus is well marked, but not very deep.

(Plate LXXXIII.)

GENUS ^Chione^

There are three species on the west coast. This genus is very closely

allied to /Venus/, and is considered by many to be only a subgenus of

the latter. All three species are white, solid, heavy shells which

exhibit the same scheme of sculpturing, namely, numerous longitudinal

ribs crossed by larger and less frequent concentric ridges.

^C. simillima^ is shaped almost exactly like the east-coast /Venus

cancellata/, but its concentric ridges are very numerous and sharp.

There is a strongly marked cordate lunule, and hardly any pallial

sinus. Length one and a half to two inches. (Plate LXXXIII.)

^C. succincta^ has fewer concentric ridges and has a large lunule.

There are purple zones within and touching the heavy cardinal

teeth. Length two and a half inches. (Plate LXXXIII.)

^C. fluctifraga^ has broad but flatter or well-rounded (not sharp)

concentric ridges, no lunule, a small ligament, a fairly deep

pallial sinus, and a finely crenulated margin (within) all around

the valves, except when interrupted by the hinge ligament. The

shell is solid and shining, and marked by deep-purple zones within.

Length one to two inches. Found in southern California.

GENUS ^Tapes^

This is a prominent genus of the /Veneridæ/. Its chief feature is

the total want of lateral teeth. There are several large species in

California.

^T. staminea, T. laciniata.^ These are the most noticeable

species. The former is sold in the San Francisco markets as the

"hard-shell clam." The shell of this species is from two to three

inches in length and of somewhat less height, rounded, and heavy.

The sculpturing consists of radiating ribs traversed by strongly

marked growth-lines. The teeth are strong, and the pallial sinus

is deep. /T. laciniata/ is much like the last, but its surface is

reticulated by a crisscross design that is very striking. It also

has a deep pallial sinus. These two species are of Southern range.

They burrow in gravelly places, among stones, between tide-marks,

and their presence may frequently be detected when walking along

the beach at low tide by seeing a sudden jet of water ejected from

a little hole in the mud or gravel. The animal, becoming alarmed at

the approach of something, suddenly snaps shut its valves, and thus

forces out some water through its siphons. The foot is very strong

and often byssiferous in this genus. (Plate LXXXIII.) [pg452]

GENUS ^Saxidomus^

^S. nuttallii.^ The last of the larger west-coast /Veneridæ/ which

we shall examine. The genus is very closely allied to /Tapes/, and

no doubt might better be considered as its subgenus. The shell is

brownish-white, three to four inches in length, and heavy, rough,

and coarse-looking, with irregular concentric ridges. There is

no lunule, but a large external ligament is very prominent just

back of the beaks. Within it is white, with a deep pallial sinus.

Just below the ligament area is a zone of translucent, agate-like

shell-structure. This large clam, with several others of the same

genus, lives in shallow water near shore.

FAMILY ~PETRICOLIDÆ~

GENUS ^Petricola^

^P. pholadiformis.^ Along the Jersey coast, especially about

Atlantic City, there are small patches of clay or hard tenacious

mud which lie just at the edge of the sea. As the beating of

the surf gradually encroaches upon these hard fragments of once

extensive clay-beds, many specimens of this curious bivalve mollusk

are washed out from their burrows in this clay and cast upon the

sandy beach. The animal has long siphons which are united about

one third of the way to their ends. Although this creature is

allied to the /Veneridæ/, the degree of mantle fusion present is

much greater, leaving in this case only a fairly long slit through

which the foot may protrude. The shell is very dissimilar to that

of any of the /Veneridæ/, and in many respects, judging from a

conventional standard, is a remarkable form. It is exceedingly

thin, is of a chalky texture, gapes widely posteriorly, and is

ornamented with transverse ribs, which are feeble upon the long

produced posterior portion of the shell, but strong in the anterior

part, where they are crossed by the coarse lines of growth, which

appear like vaulted scales upon the ribs. The color is a dull

white. There are two cardinals in each valve and no laterals.

Length one and a quarter to two and a half inches; height one half

to three quarters of an inch. This species passes its entire life

in the burrow it has made for itself in the clay. Its only motions

are made in climbing to the entrance of its burrow or in retreating

far out of sight within its depths. Its siphons are tipped with a

dark or drab color as a measure of protection from the predaceous

crabs which range about the mud surfaces near tidal marks, and are

always upon the lookout for succulent bits of flesh.

[Illustration: /Petricola pholadiformis./]

^P. carditoides.^ A petricola of the Californian coast, very

similar in its habits to the east-coast form. It bores, however,

not only into clay, but also into soft rocks in order to effect a

permanent lodgment. Often this species occupies a hole which it has

discovered already existing; in this case its shell grows to fit

the surroundings. The hinge-teeth, and sculpturing are frequently

reduced and sometimes are quite obsolete; but the shell has the

chalky, thin texture that is characteristic of the genus. [pg453]

There is another family of rock- and mud-boring bivalves which

superficially resemble the petricolas, but their anatomical

organization removes them to a little distance from the

/Petricolidæ/. They are considered further on, under the name of

/Pholadidæ/.

FAMILY ~CARDIIDÆ~

GENUS ^Cardium^

This is another important family of the /Pelecypoda/, which, with

the /Veneridæ/, the /Mactridæ/, and the /Tellinidæ/, is entitled to

distinction on account of its high organization, its high type of

shell, its universal geographical distribution, and its great beauty.

The dominant genus is /Cardium/--a name given on account of the fact

that the shell is shaped like a heart. The animal has a very long,

recurved, and surprisingly strong foot. The mantle-edges are quite

freely open to the siphonal region and are highly papillate and

waved. The siphons are usually very short, but have wide exterior

openings and are also strongly papillate about their margins. The

gills are obliquely situated, and seem to be thicker and heavier

than is usual in pelecypods; they are much folded, the outer lamella

being the smaller. With such a pointed foot and such short siphons

/Cardium/ is obviously not a deep-burrowing genus; but it does

partially bury itself in soft semi-liquid sand. Its progression is

effected by leaps which it is enabled to make by reaching far out

with its foot, then suddenly twisting to one side and throwing the

shell several inches. The shell is ventricose, is closed or gapes

slightly posteriorly, and has prominent subcentral umbones and an

external ligament. The sculpture-scheme of /Cardium/ (if the shell

is not perfectly smooth) is one of radiating ribs or ridges, which,

being regular, form a perfect crenulation of the ventral margin.

There are two cardinal teeth in the center, and one lateral tooth

upon both the anterior and the posterior side: the latter are

situated at some little distance from the beaks.

^C. magnum.^ The largest and finest "cockle" of the east coast of

the United States. It is, indeed, one of the finest cockles in the

world. The almost perfect heart-shape is striking. The posterior

side is somewhat flatly depressed. The thirty-three to thirty-seven

regularly disposed, broad, radiating ribs; the regularly crenulated

margins; the yellowish-brown color garnished with transverse rows

of chestnut or [pg454] purple lines or spots; the brownish-purple

posterior area--all combine to make this large /Cardium/ a

beautiful species. Its length is four inches; height five and a

quarter inches. It is a very abundant species on the open Florida

beaches, where it is often left exposed and alive at very low

tides. (Plate LXXXIV.)

^C. isocardia.^ This also is a Floridian species, of elongated

heart-shape and with radiating ribs. It is not more than half

as large as the last-described species. The ribs are decorated

with erect vaulting scales which are exaggerated portions

of growth-lines. The beaks are smaller in proportion than

in /C. magnum/. The shell is brown to straw-color, stained

with purplish-brown without, and has a bright salmon-red or

purplish-pink interior. The margins are deeply crenulated. The

teeth are arranged as in the last-described species. It is very

common on the beaches of western Florida. (Plate LXXXIV.)

^C. serratum^, ^C. lævigatum^. These two species have a perfectly

smooth surface, and inflated, globose, heart-shaped shells, and

are of a creamy-white color, suffused with a yellowish, golden

tint which suggests the color of butter. Some forms are shiny, and

citron-yellow and pinkish toward the margins, whence the name of

"peach-shell." Height one to two inches. Not uncommon upon Florida

beaches. (Plate LXXXIV.)

^C. mortoni.^ Another of the smooth forms of /Cardium/ (placed in

the subgenus /Lævicardium/). It occurs in Florida and also extends

up the coast to Cape Cod, being very abundant in Long Island Sound.

In the neighborhood of Martha's Vineyard and along the north shore

of Long Island this very pretty little species has been reported as

occurring in soft ground even above low-tide mark, near the mouths

of creeks. It is enough to say of it that it is a smaller edition

of /C. lævigatum/ and may be further distinguished by a purple

blotch on the posterior margin, just within the valves, the general

color within being bright yellow. In young specimens, zigzag lines

of dark fawn-color upon the pale-yellowish background of the smooth

exterior surface of the shells are a noticeable feature. The

largest specimens measure an inch in length and nearly the same in

height. The long cirri upon the siphons are striking.

[Illustration: /Cardium mortoni/, showing extended animal.]

^C. substriatum.^ A cockle of this inflated, smooth type, which

strongly resembles the east-coast form, found upon the Pacific

coast. The name indicates that it is not altogether smooth, a

fact only revealed, however, by a magnifying-glass. It is about

one half of an inch in length, and of a light drab-color, spotted

and sometimes radially lined with yellowish-brown. Professor Keep

likens this species in both shape and color to a sparrow's egg.

(Plate LXXXIV.)

[Illustration: PLATE LXXXIV. 1, Cardium magnum, much reduced. 2,

Cardium isocardia. 3, Cardium lævigatum. 4, Cardium substriatum,

enlarged. 5, Cardium corbis (young specimen). 6, Glycimeris

generosa.]

^C. elatum.^ A veritable giant among the cardiums. It is found on

the southern Californian coast, though rarely north of the Mexican

border. It is of the smooth, glossy type belonging to the subgenus

/Lævicardium/. It attains a diameter of six inches, and is of a

creamy-yellow appearance.

^C. corbis^, ^C. quadrigenarium^. These two Californian cockles

are of the ribbed type displayed in the eastern /C. magnum/ and

/C. isocardia/. /C. corbis/ is found in the northern Californian

and Puget Sound region, [pg455] and /C. quadrigenarium/ on

the southern shores of California. The former is a full, round,

heart-shaped shell with about thirty somewhat scaly ribs. The edge

of the shell is deeply toothed; the color light brownish; the

diameter from two to three inches. It preserves all the features

of the genus as regards both shell and anatomical characters. The

other species, /C. quadrigenarium/, very strongly resembles /C.

magnum/ in size and shape. It lacks the flattened area on the

posterior portion of the shell which is characteristic of the

east-coast species, and its uniform brownish-white coloration is

less striking. It has about forty regularly spaced, radiating ribs,

which are smooth upon the umbonal region, but elsewhere are armed

with spiny processes. Diameter about six inches. (Plate LXXXIV.)

[Illustration: /Cardium islandicum./]

[Illustration: /Cardium pinnulatum./]

^C. islandicum^, ^C. pinnulatum^. Both of these are cold-water

species and occur along the New England coast. The former has

a shell which varies from one half of an inch to two inches in

length, and has from thirty-six to thirty-eight sharp, three-sided,

radiating ribs, the furrows between them being rounded and wrinkled

by growth-lines. A yellowish-brown epidermis covers the shell and

bristles into a sort of fringe upon the sharp edges of the ribs.

/C. islandicum/ cannot be said to be a very common species in New

England, although collectors have so reported it. Specimens from

Massachusetts are not as large as those of more northern habitat.

It does not occur south of Cape Cod. /C. pinnulatum/ is one of the

"small fry" among the cockles. Its largest diameter is less than

one half of an inch; but what it lacks in size it seems to endeavor

to make up in abundance, for it is scattered everywhere along the

coast from New York northward. Specimens can nearly always be found

in the stomachs of fishes, which, by the way, form an excellent

hunting-ground for rare species of mollusks of small size. There

are twenty-six slightly rounded ribs, with deep linear grooves

between them. Upon the ribs, especially in the posterior portion

of the shell, are arched scales, folded so as to appear like blunt

spines. The species may easily be distinguished from the young of

/C. islandicum/ by the smaller number of ribs. The animal, /C.

pinnulatum/, is said to be exceedingly lively and able to make

rapid progress over gravelly bottom by executing sudden leaps.

It has a long, recurved, very strong foot, and its movements are

effected as described above. It is abundant at Bar Harbor. [pg456]

FAMILY ~MYIDÆ~

GENUS ^Mya^

In this family we encounter, rather suddenly, some new features not

heretofore seen in the pelecypod structure. In the first place,

the siphons are enormously large, are united, and are surrounded

by a leathery epidermis. The mantle-edges are fused together along

the entire ventral margin, except for a small slit through which

the foot may project. Although the animal may withdraw the long

siphons into its shell, yet they remain to a certain extent exposed,

for the valves gape widely posteriorly, and only slightly less

so anteriorly. In the economy of these forms the shell seems to

play a less important part than it does in the /Veneridæ/, in the

/Tellinidæ/, and generally in those families whose shells are strong

and, closing firmly, afford the animal within a real protection. The

shell of /Mya/ (the principal genus) is thin, white, and of a softer

chalky texture; it gapes widely "fore and aft," and has a loosely

constructed hinge apparatus, consisting of an erect projecting tooth,

which fits into a pit in the opposite valve.

[Illustration: /Mya arenaria./]

^M. arenaria.^ This is the common "soft-shell clam" of New England.

Its range is from Cape Cod to Greenland and Great Britain. Upon

the Maine coast it is very extensively gathered and sold to the

Banks fishermen for bait. Its use as food for man is probably not

very great, yet it is always to be seen on sale in the markets of

New England coast towns. It cannot compare in flavor with /Venus

mercenaria/, the "hard-shell clam" south of Cape Cod. /M. arenaria/

lives between tides in muddy, sandy, pebbly, or even rocky ground,

where it can find material in which it can burrow and hide itself.

It lies just below the surface, with its siphons projected into

the water. When the water recedes, /Mya/ draws in its siphons

and awaits the return of the tide, every now and then [pg457]

ejecting a jet of water into the air. The shells vary considerably

in size and thickness of valves. Large specimens are three and a

half inches long and two inches high. Our forefathers were not

always well posted upon the habits of mollusks, even though they

may have relished them in chowders and believed their flesh to

possess valuable curative properties. John Winthrop, in 1634, gave

a list of useful American animals, in which he remarked: "Clam,

white; their broth is most excellent in all intermitting fevers,

consumption, etc. These clams feed only on sand." What marvelous

digestive powers!

[Illustration: /Mya arenaria/, showing extended animal.]

FAMILY ~SOLENIDÆ~

[Illustration: /Ensis directus/, showing extended animal: 1, foot; 2,

siphons; 3, papillæ, enlarged.]

In this family are included the long, slender bivalves commonly

known as "razor-shells." Every one who has been to the sea-shore has

become familiar with these odd-looking mollusks, for their valves

are always to be found upon every beach. Their station is upon sandy

flats or bars more or less exposed at low tide. They burrow into

the sand perpendicularly to a depth of two or three feet, remaining

hidden most of the time. Occasionally a colony of them will be seen,

each one projecting slightly from his burrow. If approached most

cautiously some of them may be captured, but if the sand is jarred

they all take fright and disappear in an instant. It is no easy

matter to capture a "razor" when once he has taken warning, for he

will dig down into the sand about as fast as one can follow with a

spade. A good way to catch one is to approach his burrow carefully,

and then plunge a spade obliquely down below him, thereby [pg458]

cutting off his retreat. So tenaciously will they cling to the sand

by expanding the muscular foot that the shell may be pulled entirely

off the body before they will let go.

GENUS ^Ensis^

^E. directus^ (^Solen ensis^, ^Ensis americanus^). The common

species upon the New England and Jersey coasts. The foot is long,

and protrudes from one end of the long shell; it is also very

strong, and capable of change at will into almost any form, from a

pointed bulb to a flat disk. The siphons, which project from the

opposite end of the shell, are short and are not united. The gills

are long. The juxtaposition of these organs is at first confusing,

because the greatly elongated form of the shell and the habits of

the animal in burrowing vertically into the sand have caused the

foot to be pushed farther away from the posterior portion of the

shell and to protrude in a direction just opposite to the siphons.

The shells are bent or slightly curved; they gape at both ends; and

they are fitted with very small interlocking teeth at the upper

corner of the posterior end. The color is white, but a yellowish or

greenish glossy epidermis covers the entire test. Length about six

inches. The manner in which the animal makes its rapid descent into

the sand is very interesting. First extending the foot lengthwise

into a point, it plunges it into the sand; then, by forcing water

into the organ it expands it, thus pushing away the sand on all

sides; and still further expanding the foot at the end into a disk,

it secures an anchorage which enables it to draw down its shell. By

quick repetition of this process /Ensis/ can get out of sight in a

remarkably sudden manner.

[Illustration: /Ensis directus./]

GENUS ^Solen^

^S. viridis.^ A smaller species, about two inches in length, and

with a nearly straight light-green shell. It is often abundant from

New Jersey southward.

^S. sicarius.^ The common Californian species of Northern range. It

is only about two inches long, and is rounded anteriorly, but is

chopped off squarely behind. It is slightly curved and white, and

has a glossy brown epidermis.

^S. rosaceus.^ Another species of Southern range, very similar

in form to the last, but straighter and rosy-white in color. The

epidermis is glossy brown. Length two inches. [pg459]

GENUS ^Tagelus^

^T. gibbus.^ The extended range and shore station of this

exceedingly abundant species will cause it to be among the first

accessions to the cabinet of the collector south of Cape Cod. It

burrows deep in sand and mud, leaving two small openings to the

hole for the accommodation of its two excessively long siphons.

As in /Solen/ and /Ensis/, the foot is large and muscular,

tongue-shaped, and capable of remarkable change of form and great

freedom of movement. The long white siphons, separated from the

base and each provided with orange-colored eyes (or, rather, a

rudimentary sort of visual organs), are the most important feature.

The apex of the hinge is not, as in /Solen/ and /Ensis/, at the

end of the shell, but is more conventionally placed near the

middle; the cardinal teeth are very small, two upon each valve

and interlocking; a flat, oblong, callous process serves as a

fossette. The dorsal and ventral margins are parallel, and gape

at both ends; the shell is white, and is covered with a dense

yellowish epidermis, which, passing the ventral margin, appears to

become continuous with the thickened mantle-edge. There is no other

species north of Hatteras with which this could be confounded.

The double entrance to the burrow, which may be discovered about

low-tide mark, is unique. /T. gibbus/ is a good species to examine

for the crystalline stylet in the digestive tract.

[Illustration: /Tagelus gibbus/, showing extended animal.]

[Illustration: /Tagelus gibbus./]

FAMILY ~GLYCIMERIDÆ~

GENUS ^Glycimeris^

^G. generosa.^ A large shell of the Pacific coast, occurring

most abundantly in Puget Sound waters, where it frequents muddy

shallows. It is a remarkable pelecypod in respect to its siphons

and the degree of mantle fusion. The appearance of the animal

is that of a huge pair of [pg460] united siphons, protected

laterally at their larger end by two white, widely gaping valves.

The very small pedal opening in the line or mantle juncture

indicates a very small foot. (Plate LXXXIV.)

FAMILY ~PHOLADIDÆ~

There is a striking resemblance between the shells of this

rock-boring family and those of the petricolas--a resemblance which

consists principally in the texture of the shell and the tendency

to different types of sculpturing upon the posterior and anterior

surfaces of the valves.

GENUS ^Pholas^

In /Pholas/ the anterior part of the hinge-margin is reflected back

over the umbones, and a long rib-like tooth springs from under the

umbonal region and curves out almost to the center of the valves.

The shell gapes "fore and aft," and is thin, white, very hard, and

brittle. The animal has a short, truncated foot and a small orifice

in the mantle through which the foot may be projected. The siphons

are long and are united almost to their ends. Dorsally, an exposed

portion of the animal is protected by accessory calcareous plates.

The habits of /Pholas/ are very interesting. It is found in holes

gouged out of solid rock or out of pieces of wood; sometimes, like

/Petricola/, it may be found excavating in hard clay. As the anterior

end of a /Pholas/ shell is the larger in diameter, and is the end

which is most deeply buried in the rock (the opening of the burrow

being comparatively small), there was some mystery as to the way

in which the creature manages to get inside its rocky dwelling.

Observations in aquaria have shown that the young /Pholas/ begins his

process of home-building very early in life. The wearing away of the

stone is effected by constantly turning the shell around, scraping

with the anterior edges of the valves. A lodging-place having been

secured, /Pholas/ is obliged to work constantly to enlarge his burrow

for the accommodation of his growing shell. The long siphons may

project from the hole and draw in food and breath, but the animal is

a prisoner for life. When /Pholas/ has withdrawn his long siphons

he is reasonably secure from his enemies, but [pg461] nevertheless

thousands of them are destroyed by predatory starfishes, who know

how to get at their victims. The restless crustaceans, ever on the

outlook for a meal, often nip the siphons of the rock-dwellers, and

a kind of worm sometimes attacks them, and, destroying the animal,

proceeds to occupy the empty shell and burrow.

^P. costata.^ This species has a wide geographical range, being

found from Cape Cod to South America, but it is not abundant north

of Hatteras. In Florida it burrows deep in sand as well as in wood

or rock. On account of its white color and suggestive shape and

sculpture, it has received the popular name of "angel's-wings." It

grows to a length of seven or eight inches.

[Illustration: /Pholas costata./]

^P. truncata.^ This has much the same range as the last, but is

more commonly to be found in New England waters. It also burrows

in any hard substance, or in mud above low-water mark. It is

especially common in peat-banks.

[Illustration: /Pholas truncata./]

^P. californica.^ A Californian /Pholas/. The shell is about three

inches in length, and resembles in all features and habits the

/Pholas/ of the east coast. Differences in the shell indicate that

it is a distinct species.

GENUS ^Zirphæa^

^Z. crispata.^ A species of Northern range, occurring but sparingly

in New England, in hard clay or rocky burrows. It may be identified

at once by the furrow which passes from the beaks across the valves

to the lower edges of the shell and divides the surface of the

valve into two areas. The anterior area is decorated with radiating

toothed ribs; the posterior area is smooth. This conchological

feature of the genus is very [pg462] curious; it may be observed

also in several deep-sea genera and in certain extinct fossil

forms. The length of this shell is about two inches. This species

also occurs in California, where its favorite station is in hard

tenacious clay. Length two to four inches.

[Illustration: /Zirphæa crispata./]

FAMILY ~TEREDINIDÆ~

GENUS ^Teredo^

^T. navalis.^ This species is worm-like in form, but it has a small

bivalve shell at the larger end, and near the anterior extremity

two calcareous appendages called pallets, beyond which extend two

siphons. Along the surface of the mantle is secreted a continuous

shelly tube which lines the burrow. This mollusk, commonly called

the "ship-worm," is exceedingly destructive, perforating with its

burrows submerged timber and soon rendering it useless. Various

means are taken to protect ships, the piles of wharves, buoys, and

the like, against its ravages; copper sheathing, large-headed nails

driven close together into the wood, verdigris paint, and so on,

being used with more or less effect. Vast numbers of these animals

enter the wood and burrow in various directions, but they never

interfere with one another, a thin partition of wood always being

left between adjacent burrows. How they effect the burrowing is

not determined, but it is supposed to be by means of the pallets.

/Teredo/ does not, like the boring isopod /Limnoria lignorum/, feed

upon the wood. Its food consists of microscopic organisms which

are taken in through the incurrent siphon. In temperate waters /T.

navalis/ grows sometimes to the length of six inches; in tropical

waters it attains the length of two feet.

[Illustration: /Teredo navalis/, in a piece of timber: /P/,

pallets; /SS/, siphons; /T/, tube; /V/, valve of shell.]

There are three other species of /Teredo/ and one of the genus

/Xylotrya/ on our Northern shores; /T. navalis/ is, however, the

most common and most destructive. In Southern waters there are many

other forms of these boring mollusks. [pg463]

FAMILY ~PANDORIDÆ~

GENUS ^Pandora^

[Illustration: /Pandora trilineata./]

^P. trilineata.^ A little New England shell, remarkable on account

of its extreme flatness. When looking at this shell before opening

it, one naturally wonders where the animal finds room to exist

between two such disk-like valves. The animal is very thin, with

largely united mantle-edges, widely separated feeble adductor

muscles, and a fairly large tongue-shaped foot. The shell is

nacreous, rounded anteriorly, and produced posteriorly into a sort

of upturned tip which gapes to accommodate two little siphons. The

dorsal hinge-margin is excavated and curved. Length about one inch.

It is abundant at Cape Cod, in sandy stations, on oyster-beds, and

is found from Maine to Florida. [pg464]

TABLE SHOWING THE CLASSIFICATION OF THE CEPHALOPODS DESCRIBED IN THIS

CHAPTER

CLASS =CEPHALOPODA=

Orders Genera Species

Subclass =Tetrabranchiata=

^Nautilus^

Subclass =Dibranchiata=

~OCTOPODA~ ^Octopus^

^Argonauta^ ^A. argo^

~DECAPODA~ ^Spirula^

^Ommastrephes^ ^O. illecebrosus^

^Sepia^

^Loligo^ ^L. Pealei^

^L. brevis^

CLASS =CEPHALOPODA=

The /Cephalopoda/ form a singularly isolated group, and are so

superior in organization and intelligence to all other mollusks

that it is difficult to believe that they are first cousins to the

lethargic gasteropod and the simply constructed bivalve. But the

class bears the stamp of its origin in a mantle, a radula, and a

disposition of internal organs and functions which, although highly

perfected, is essentially molluscan.

Along the Atlantic coast of the United States, particularly in its

northern portion, occur several examples of cephalopods belonging to

the genera /Ommastrephes/ and /Loligo/, all the species of which are

referred to, in common parlance, as "squids." They frequent shallow

water, and are often to be found in weirs, darting about with rapid,

spasmodic movements, or perhaps lying motionless on the bottom.

The squids enter the weirs for the purpose of capturing the young

mackerel which are caught in these traps. The squid lies quietly upon

the bottom, which it simulates so closely in color as to be almost

invisible, and when [pg465] a school of fishes swims over it, darts

suddenly into the midst of it, seizes a fish with its sucker-bearing

arms, and kills it by the bite of its parrot-like beak or jaws.

Sometimes it happens that squids, while pursuing fish too near shore,

precipitate themselves upon the beach, where they flounder about,

ejecting water from their siphons, which pushes them only farther

away from the water, and squirting out "ink" from their ink-sacs in

a vain endeavor to hide themselves from view. On bright moonlight

nights squids often go ashore in vast numbers, and perish within a

few inches of their native element, which they seem to be unable

to regain. These creatures usually swim backward, and the theory

is that, dazzled by the bright light of the moon, they continue to

gaze at it while swimming, and if there happens to be a shore in the

direction of their movements, they suddenly find themselves beached.

The fishermen of Canada and New England take advantage of this habit

and capture great quantities of squids by placing bright lights in

the bows of their boats and then rowing toward shore, thus driving

the squids out of the water. The Banks fishermen use them as bait

for catching cod. The right claimed by American fishing-schooners to

purchase squids in Newfoundland has helped to keep alive the quarrel

between Canadian and American fishermen, which has vexed their

respective governments for many years.

The range in size among the species of this class is very remarkable.

The little sepiolas are about an inch long; the squids of our

coasts vary in length from eight inches to one foot; and the giant

/Architeuthis/ of the North Atlantic measures, often, fifty feet

from the end of its arms to the tip of its tail. Such a creature,

with its long arms provided with suckers, its powerful jaws, and its

rapid, alert movements, is a formidable foe. These animals have been

the basis of many legends about sea-serpents and sea-monsters. A

gruesome story of an octopus is told by Victor Hugo in "The Toilers

of the Sea," where he gives a thrilling account of a man's encounter

with a devil-fish in a cave. One who has read this tale has a vivid

picture in his mind of the giant squid, and the danger of meeting

one of these many-armed foes. Victor Hugo's devil-fish, [pg466]

however, is an animal not true to nature, but a composite, having

the attributes of the polyp and of the octopus, and the name of a

large ray of Southern waters, a real fish, the /Cephaloptera/, known

in its localities as devil-fish. This monstrosity of the novelist's

imagination has, however, done more to acquaint the general public

with these interesting cephalopods than have the descriptions of

scientists.

The giant squid, which is such a dangerous foe, has its own enemy in

the sperm-whale. The cachalot swims through the water with its lower

jaw hanging, the cephalopod grasps the jaw, and the whale then shuts

his capacious mouth upon it. Whalemen describe conflicts between

these enormous creatures, the whale always being the conqueror.

Sperm-whales killed by man often eject great quantities of the squids

in their death throes, showing this food to be almost their exclusive

diet.

The name "cephalopod," meaning "feet around the head," is descriptive

in part of their anatomy. The head is usually marked off by a

neck-constriction, and it bears two highly organized eyes. The foot

is fused in part with the head above the eyes and around the mouth;

on the upper side it is divided into eight or ten long arm-like

processes, bearing suckers, which act as organs of prehension. The

under part of the foot forms a tube called the funnel. Through the

funnel the animal expels water from the mantle cavity, and thus

propels itself through the water.

The mantle covers the body of the animal, and is a cup-shaped or

conical envelope, open only at the anterior end, through which

project the head and siphon or funnel. It is attached to the body by

a line on the dorsal side, the anterior margin being free and open,

but provided with an arrangement of cartilages by which it can be

hooked on to the siphon, thus completely closing the entrance to

the mantle cavity. The mantle is very muscular, and is constantly

expanding and contracting, taking water into the mantle cavity

through the mantle opening for respiratory purposes, or expelling

it through the siphon for propulsion; in the latter case the mantle

opening is closed at the moment of ejecting the water. When the

siphon is in its normal position [pg467] the animal swims backward;

but it can be turned back over the edge of the mantle, giving a

forward movement.

The surface of the mantle is covered with pigment-cells

(/chromatophores/). There are sets of chromatophores containing

different colors. The cells are opened or closed at will by muscular

action of their walls. When open the cells seem to fuse together,

giving a solid color-surface, or spots of color as desired, in blue,

red, yellow, or brown; when closed they seem as specks on the almost

transparent tissues of the animal. Flashes of changing color follow

one another with great rapidity over the living animal. In swimming

it assumes the color of its surroundings.

Another curious means of protection possessed by the dibranchiate

cephalopods is an ink-bag, the brown or black secretions of which are

ejected through the siphon, clouding the water when the animal wishes

to escape from danger. The ink taken from the ink-sac of /Sepia/ is

an article of commerce.

Only /Nautilus/ and the female /Argonauta/ have the characteristic

external shell of mollusks. In all other forms the shell is internal

or is invested in the integument of the mantle. Of such is the

cuttlebone of commerce, which is a calcareous leaf-like body obtained

from /Sepia/, the cuttlefish. The common squid /Loligo/ has a horny

substance situated in the dorsal side of the mantle, called the pen.

/Spirula/ has a spiral internal shell divided into chambers. Vast

numbers of these shells are cast upon the beaches of the Pacific

Islands, and they have also been found on the shore of Nantucket.

Cephalopods are separated into two subclasses. In the first, the

/Tetrabranchiata/, there are four branchiæ, four nephridia, and four

auricles. They are without an ink-sac, and have the foot divided into

lobes bearing sheathed tentacles. /Nautilus/ is the only genus.

SUBCLASS =TETRABRANCHIATA=

GENUS ^Nautilus^

Probably the best-known cephalopod is /Nautilus/--the pearly-shelled,

chambered nautilus made immortal in the beautiful poem of Oliver

Wendell Holmes. The shell of /Nautilus/ is a flat spiral; the

interior is divided by septa forming a series of chambers; [pg468]

the septa are perforated, and through the opening runs a tube or

prolongation of the body, the siphuncle, which extends to the tip of

the shell. The chambers are filled with gas. The animal in the course

of its growth moves forward into a newly formed chamber and builds a

new septum, closing the cavity last occupied. /Nautilus/ lives among

the coral reefs of the southern Pacific. Its four or five species are

the remnants of a once very extensive race of cephalopods. The fossil

remains of many species of /Nautilus/, together with various other

genera of shell-bearing cephalopods, indicate that this group has

seen its best days. The dibranchiate genera, however, appear to have

reached their maximum at the present day.

SUBCLASS =DIBRANCHIATA=

[Illustration: /Argonauta argo/, female removed from shell.]

The second subclass, the /Dibranchiata/, is characterized by two

branchiæ and two auricles. The main part of the foot is divided into

eight or ten long arms provided with numerous suckers arranged in

from one to four rows on the ventral side of the arms. They have

also an ink-sac. The /Dibranchiata/ are divided into two orders: the

/Octopoda/, which have eight arms, and comprise the /Octopus/ and

/Argonauta/; and the /Decapoda/, which have ten arms, and comprise

/Spirula/, /Ommastrephes/, /Sepia/, and /Loligo/. In these animals

two of the ten arms are longer than the others, and these tentacular

arms have suckers only on their broadened, club-like ends, they are

kept retracted within grooves, one on each side of the head, except

when needed for prehension. [pg469]

GENUS ^Argonauta^

^A. argo.^ In this species, the paper-nautilus, the shell, which is

possessed only by the female, is not chambered. The animal rests in

the shell, but has no organic connection with it other than by the

membranous expansions at the extremities of the two dorsal arms,

which secrete it and hold it in place. The purpose of the shell is

to hold and protect the eggs.

[Illustration: /Argonauta argo/, side view of shell.]

GENUS ^Loligo^

^L. Pealei.^ In this species the body is cylindrical, tapers to a

point, and has a flat appendage in front. The fins are terminal,

half, or more than half, as long as the body, united in a point

posteriorly, and obtusely rounded on the outer angles. The head

is a little narrower than the mantle. There are eight sessile,

sub-triangular arms furnished with two series of suckers which

are hemispherical and stalked, and two long retractile tentacular

arms dilated at the extremities, bearing four rows of suckers. It

has a pen- or quill-shaped cartilaginous substance in the dorsal

integument of the mantle. Common from Cape Cod to South Carolina.

^L. brevis.^ A small short-bodied species, with short rounded

caudal fins. It is common from South Carolina to Florida, and

extends as far north as Delaware Bay.

[Illustration: /Loligo Pealei/, young female; dorsal view.]

GENUS ^Ommastrephes^

[Illustration: /Ommastrephes illecebrosus/, young male; ventral view.]

^O. illecebrosus.^ A species similar to /L. Pealei/, but with

shorter fins. These are broad and pear-shaped, one third wider than

they are long, and usually reach less than one half the length of

the mantle. They are straight on the posterior end, and form nearly

a right angle, while the upper margins are rounded. The head is

as broad as the mantle. The arms are stout and taper to an acute

point. The tentacular arms are long when expanded. The species

is abundant from Cape Cod to Newfoundland, and is found as far

south as Newport, Rhode Island. This is the squid which is used so

extensively in the Banks fishery as bait. It [pg470] visits the

shores in large schools, presumably in pursuit of prey, and often

itself becomes the victim. It is a beautiful creature from its

varying colors, which are truly wonderful. It changes in a moment

from vivid red to deep blue, purple, orange, and so on, the colors

often passing over it in flashes as it swims along. [pg471]

VIII

CHORDATA

TABLE SHOWING THE CLASSIFICATION OF THE CHORDATA DESCRIBED IN THIS

CHAPTER

Phylum =CHORDATA=

Class =UROCHORDA= or =TUNICATA=

Order =LARVACEA= (/Free-swimming, pelagic; Tunicata having

caudal appendages/)

Genera Species

^Appendicularia^

Order =THALIACEA= (/Free-swimming Tunicata, without caudal

appendages; single or in colonies; muscles of body-wall

arranged in complete or in interrupted ring-like bands/)

Suborder =CYCLOMYARIA= (/Cask-shaped bodies with complete

rings of muscular bands; oral and atrial apertures at

opposite ends of the body/)

^Doliolum^

Suborder =HEMIMYARIA= (/Spindle-shaped bodies; muscular bands

in incomplete rings; oral and atrial apertures subterminal/)

^Salpa^

Suborder =PYROSOMATA= (/Hollow cylindrical colonies; zoöids

embedded in a gelatinous wall; oral apertures open on

the outer, atrial apertures open on the inner surface of

cylinder/)

^Pyrosoma^

Order =ASCIDIACEA= (/Mostly fixed Tunicata; single or in

colonies; tests of considerable thickness/)

Suborder =ASCIDIA SIMPLICES= (/Possess distinct tests;

usually permanently fixed/)

Genera Species

^Molgula^ ^M. manhattensis^

^M. pellucida^

^M. arenata^

^Cynthia^ ^C. pyriformis^

^C. partita^

^C. carnea^

^Boltenia^ ^B. clavata^

^Ascidia^ ^A. amphora^

^A. callosa^

Suborder =ASCIDIA COMPOSITÆ= (/Fixed colonies; the zoöids

embedded in a common gelatinous material; without separate

tests/)

^Botryllus^ ^B. gouldii^

^Amar[oe]cium^ ^A. pellucidum^

[pg474]

CHORDATA

CLASS =UROCHORDA= or =TUNICATA=

The most conspicuous animals of this class are the ascidians, which

are common objects on rocky coasts. The /simple ascidians/ are

peculiar leathery, sac-shaped bodies which send out jets of water

when touched. This habit gives them the common name of "sea-squirts."

Some are highly colored, especially those of Southern waters; others

are somber, unattractive bodies, often growing in masses. The

/compound ascidians/ are gelatinous colonies, sometimes forming thin

incrustations, sometimes jelly-like masses, on seaweeds, shells,

etc. This class comprises also the beautiful /Salpa/, a genus of

free-swimming animals having transparent bodies encircled by rings of

muscular bands, and in one stage forming chains of attached organisms

which swim on the surface of the sea and of bays.

The tunicates are by some authors classed with the vertebrate

animals because in the larval stage they have a notochord; this

disappears, however, in the adult form, and the animals are

considered degenerates. The tunicates are interesting to biologists

from the remarkable changes they undergo in their life-history, and

(in some genera) the marked phase of alternation of generation. One

of their curious anatomical features is the blood-vascular system.

The circulation is propelled by wave-like contractions of the heart,

which, after forcing the blood one way for a time, stops and reverses

the blood-current. The tunicates are widely distributed, and occur at

all depths. (Plate LXXXV.) [pg475]

GENUS ^Salpa^

[Illustration: /Salpa/ chain.]

The animals of this genus are transparent, subcylindrical, smooth,

gelatinous bodies encircled by bands of white muscular fiber. They

strikingly exemplify alternation of generations. They occur in two

distinct conditions, one being solitary, the other consisting of

animals united in chains. The solitary individuals are about an inch

long, and have two long processes at the posterior end. These single

animals reproduce by budding, and form series of individuals in small

chains, the animals being arranged in two rows. The chains grow to

the length of a foot or more, and contain twenty to thirty pairs

of salpas. Each of these connected individuals produces in turn a

single egg, which becomes a single /Salpa/, and this again, like its

grandmother, reproduces by budding. Thus the animals are alike only

in alternate generations. The naturalist Chamisso, who discovered

the relationship between the two forms, expressed it as follows: a

/Salpa/ mother is not like its daughter or its mother, but resembles

its sister, its grandmother, and its granddaughter. The single zoöids

liberate many colonies during the summer, which grow rapidly, and in

the autumn the chains are exceedingly abundant. The /Salpa/ chains

swim about with a serpentine movement, and are beautiful, delicate

objects with their transparent bodies banded with white, tinged with

pink, and streaked with blue.

SIMPLE ASCIDIANS

These are solitary and usually fixed; they are never free-swimming,

and when in colonies each animal has a distinct test. All the larger

ascidians, or sea-squirts, belong to this group.

GENUS ^Molgula^

Body more or less globular, membranous, attached or free; orifices on

very contractile tubes.

^M. manhattensis.^ Nearly globular when the tubes are contracted;

usually covered with bits of eel-grass, seaweeds, sand, etc.;

surface a [pg476] little rough; color olive-green. The animal is

often attached to rocks, more frequently to eel-grass and seaweeds,

and is sometimes so crowded as to form large clusters. Found from

Maine to North Carolina.

^M. pellucida.^ Body nearly globular, about an inch in diameter,

smooth, clean, and translucent, the intestine showing through the

test. The two tubes are large, swollen at the base, and divergent.

The animal lives free in the sand, and is found from Massachusetts

to North Carolina.

^M. arenata.^ Body somewhat compressed laterally; test thin and

covered completely with sand, which is closely adherent; about

three quarters of an inch in diameter; tubes short and wide apart.

Found on shelly and sandy bottoms of bays and sounds.

GENUS ^Cynthia^

The animal is attached, the body coriaceous, and the orifices

four-lobed. Frequently associated in groups, the individuals often

differing in color.

^C. pyriformis.^ Body globular, or oblong when extended; hard,

velvety, whitish surface, with pink cheeks; orifices on prominent

protuberances on the upper surface. It lives in clear, deep water

on rocks, and is sometimes found at low-water mark on the northern

New England coast. Commonly called the sea-peach. (Plate LXXXV.)

^C. partita.^ Body oblong; attached; test horny and wrinkled;

rusty-brown; apertures square, on prominent tubes marked with

triangular spots of white and purple; diameter one inch. Found on

the piles of wharves and on shelly bottoms in shallow water; also

on the under side of stones when they are much flattened.

^C. carnea.^ Test low and flat, with a thin margin; adherent by a

very broad base; orifices small, square, slightly prominent; red

or flesh-color. Found in deep water on stones and shells on the

northern New England coast.

GENUS ^Boltenia^

Body more or less globular, on a long stem; fixed; orifices on the

side.

^B. clavata.^ Body long, wrinkled, leathery, on a long stalk,

resembling the flower of lady's-slipper (/Cypripedium/); two

cross-shaped orifices wide apart on the side; yellowish in color;

attached to stones in deep water, but sometimes washed ashore in

storms. The stalks are often covered with polyzoans and hydroids.

(Plate LXXXV.)

[Illustration: PLATE LXXXV. ASCIDIANS. 1, Ascidia callosa. 5, Cynthia

placenta. 2, Botryllus Schlosseri. 6, Glandula fibrosa. 3, Cynthia

pyriformis. 7, Cynthia condylomata. 4, The same, enlarged. 8,

Boltenia clavata. 9, Cynthia echinata.]

GENUS ^Ascidia^

Test gelatinous or cartilaginous; attached; it grows in bunches

under stones at low-water mark. Sometimes it is variously [pg477]

colored, but otherwise it is repulsive in aspect. The apertures are

wide apart; one orifice is eight-lobed, the other six-lobed.

^A. amphora.^ Form usually globular, but more or less irregular;

substance something like rubber. Found of all sizes adhering in

clusters to stones, shells, and piles, and usually covered with

marine growths. The color is grayish-brown.

^A. callosa.^ Body depressed, usually oval, but varying in shape;

thick, fleshy, translucent; surface uneven; apertures dark purple

and prominent. Found at low tide adhering to stones and shells.

(Plate LXXXV.)

COMPOUND ASCIDIANS

Ascidians of this group form fixed colonies, and are embedded in

gelatinous material, the animals having a common test, but not being

united by any internal union. The colonies thus formed are flat and

incrusting, or are branched and lobed, or sometimes elevated on

stalks. The zoöids are in some cases dotted irregularly over the

entire surface, in others are in rows, or again are in groups. They

have various colors--purple, yellow, blue, gray, and green. They are

common on eel-grass, the piles of wharves, the bottoms of boats, and

so on.

GENUS ^Botryllus^

^B. gouldii.^ This species forms thick, fleshy, translucent

incrustations, often several inches in length and a quarter of an

inch wide, over eel-grass, the piles of wharves, and other objects.

Sometimes, at the end of summer, small objects are completely

covered with the luxuriant growth of this compound ascidian. The

zoöids form circular or elliptical groups, often as many as fifteen

surrounding each orifice, looking like minute stars. The colonies

vary in color. Often on the same stem of eel-grass will be found

separate colonies varying in this respect. In some the ground-color

will be olive-green specked with white, while the zoöids are

purple, marked with other colors; again the arrangement is quite

different.

GENUS ^Amaræcium^

^A. pellucidum.^ A massive compound ascidian, smooth, translucent,

and gelatinous, which forms large, hemispherical, complex,

irregular masses six inches or more in diameter. It is usually

covered by adhering sand. The mass consists of club-shaped lobes,

which rise from a common base. Each lobe contains a central orifice

around which long, slender zoöids, sometimes an inch long, are

grouped. These masses are so abundant in some places that they

cover the bottom for considerable spaces. They are found in deep

water from Cape Cod to North Carolina. [pg479]

INDEX

Heavy-faced type is used to indicate names of classes, orders,

genera, etc.; heavy-faced numerals to indicate the place where the

fullest description is given

A

Abdomen, 243, =246=.

Abductor muscles, =302=.

Aboral, 202.

Surface, 201.

Abyssal, =23=.

Acalephs, =134=.

=Acanthalithodes=, 240, =271=.

=A. hispidus=, 240, =271=.

=Acephala=, 409.

=Acetabularia=, 51, =57=.

=A. crenulata=, 51, =57=.

=Acmæa=, 9, 309, 312.

=A. mitra=, 324, =357=.

=A. patina=, 324, =357=.

=A. testudinalis=, 41, 42, 324, 343, 348, =356=.

=A. testudinalis=, var. =alveus=, 324, =357=.

=Acmæidæ=, 324, 356.

Acontia, =145=.

Acorn-shell, =254=.

=Actiniaria=, 141, =142=, 143, 144.

=Actinozoa=, 112, 115, 141, =142=.

=Adamsia palliata=, 144, =267=.

Adductor muscles, =302=, 413, 417.

=Æolididæ=, 324.

=Æolis=, 41, 42, 309, 324, =354=.

=Æ. papillosa=, 324, =354=.

=Æquoreidæ=, 116, =128=.

=Ætea=, 188, =194=.

=Æ. anguinea=, 188, /194/.

=Agarum=, 36, 42, 63, 68, =69=.

=Aglaophemia=, =127=.

=A. struthioides=, 116, =127=.

=Ahnfeldtia=, 76, =82=.

=A. plicata=, 76, =82=.

=Alaria=, 63, =69=.

=A. esculenta=, 41, 42, 63, =69=.

=Albunæa=, 240, =269=.

=A. gibbesii=, 240, =269=.

=Alcyonacea=, 141, =151=.

=Alcyonaria=, 141, 142, =150=, 152.

=Alcyonidium=, 189, 192, =197=.

A. hirsutum, 189, =197=.

=A. hispidum=, 189, =198=.

=A. parasiticum=, 189, =198=.

=A. ramosum=, 189, =197=.

=Alcyonium=, 141, =151=.

=A. palmatum=, 141, =150=, 161.

Aleutian province, =311=.

=Algæ=, =25=, =48=, 62, 76.

Botanical facts about, =25=.

Alternation of generation, =120=, 121.

=Amar[oe]cium=, 473, =477=.

=A. pellucidum=, 473, =477=.

Ambulacra, 201, 202, =205=, 214, 218.

Ambulacral groove, 205.

Ossicles, =205=.

Zones, 201, 202, =205=, 218, 229.

American division, =24=.

=Amphictenidæ=, 162, =183=.

=Amphineura=, 300, 316, 317, 320, =321=, 323.

=Amphipoda=, 242, =289=.

=Amphissa=, 312.

=A. corrugata=, 326, =389=.

=Amphitrite=, 161, =182=.

=A. ornata=, 161, =182=.

=Amphiura=, 213, =215=.

=A. squamata=, 213, =215=.

Ampullæ, 201, =205=, 206, 218.

=Anadyomene=, 51, =57=.

=A. flabellata=, 51, =57=.

Anatomy, 20.

Of higher Crustacea, =246=.

Anemone Cave, =40=.

Angel's-wings, 461.

Animal-flowers, =142=.

Animal life in its lowest forms, =21=.

=Annelida=, 305.

=Annulata=, 159, 161, 164, 170.

=Anomia=, 405, =424=.

=A. aculeata=, 405, =425=.

=A. lampe=, 405, =425=.

=A. simplex=, 405, =424=.

=Anomiidæ=, 405, =424=.

=Anomura=, 240, =264=.

Antennæ, 243, =246=, 258.

Antennules, 243, =246=, 258.

=Antheneidæ=, 204, =209=.

=Anthomedusæ=, =116=.

Aperture, =302=.

Apex, 343.

=Aphrodite=, 161, =174=.

=A. aculeata=, 161, =174=.

=Aphroditidæ=, 161, 172, =173=.

=Aplacophora=, 300, 321, =323=.

=Aplysella violacea=, 105.

=Aplysia Wilcoxii=, =352=.

=Aplysiidæ=, 324.

=Apoda=, 228, =233=.

=Appendicularia=, 472.

=Arabella=, 161, =179=.

=A. opalina=, 161, =179=.

=Arbacia=, 217, =222=.

=A. punctulata=, 217, =222=.

=Arbaciadæ=, 217, 222.

=Arca=, 310, 405, =425=.

=A. noæ=, 405, =426=.

=A. pexata=, 405, =425=.

=A. ponderosa=, 405, =426=.

=Arcachon=, 434.

=Architeuthis=, 465.

=Arcidæ=, 405, =425=.

Arctic province, =309=.

=Arctica=, 406, =441=.

=A. islandica=, 406, =441=.

=Arenicola=, 162, 172, =184=.

=A. marina=, 162, =184=.

=Arenicolidæ=, 162, =184=.

=Argonauta=, 464, 467, 468.

=A. argo=, 464, =469=.

Aristocratic genera, 313, 377, 398, 401.

Aristotle's lantern, =203=.

=Arthrocladia=, 62, =67=.

=A. villosa=, 62, =67=.

=Arthropoda=, 238, =244=.

=Arthrostraca=, 242, =289=.

=Articulata=, 188.

=Ascidia=, 473, =476=.

=A. amphora=, 473, =477=.

=A. callosa=, 473, =477=.

=A. compositæ=, 473.

=A. simplices=, 473.

=Ascidiacea=, 473.

Ascidians, 8, 474.

Compound, 474, =477=.

Simple, 474, =475=.

=Ascophyllum=, 63, =73=.

=A. nodosum=, 43, 63, 73.

=Asperococcus=, 62, =66=.

=A. echinatus=, 62, =66=.

=Astacoidæ=, 240, =261=.

=Astarte=, 309, 406, =440=.

=A. castanea=, 406, =441=.

=A. undata=, 406, =441=.

=Astartidæ=, 406, =440=.

=Asterias=, 204, =212=.

=A. Forbesii=, 204, 207, =212=.

=A. gigantea=, 204, 207, =212=.

=A. ochracea=, 204, =212=.

=A. vulgaris=, 43, 204, 207, =212=.

=Asteriidæ=, 204, =212=.

=Asterina=, 204, =210=.

=A. folium=, 204, =210=.

=A. miniata=, 204, =211=.

=Asterinidæ=, 204, =210=.

=Asteroidea=, 200, 204, =205=.

=Astræa=, 141, 146, 147, =148=.

=Astrangia=, 141, =150=.

=A. danaë=, 13, 141, =150=.

=Astropecten=, 204, =209=.

=A. articularis=, 204, =209=.

=Astropectinidæ=, 204, =208=.

=Astrophyton=, 213, =215=.

=A. Agassizii=, 213, =215=.

=Astyris gausapata=, 326, =389=.

=Asymmetrical=, 328.

=Aurelia=, 133, =137=.

=A. flavidula=, 133, =137=.

=Auricula=, =231=.

=Auriculata=, 201.

=Avicula=, 405, =431=.

=A. atlantica=, 405, 431.

=Avicularia=, 190, =193=.

=Aviculidæ=, 405, =430=.

B

=Balanus=, 239, 250, =254=.

=B. balanoides=, 239, =255=.

=B. crenatus=, =256=.

=B. eburneus=, 239, =255=.

=B. geniculatus=, 239, =256=.

=B. ovularis=, =255=.

=B. rugosus=, 239, =256=.

=B. tintinnabulum=, 239, =256=.

=Bangia=, 78, =96=.

=B. fusco-purpurea=, 43, 78, =96=.

=Bangiaceæ=, 78, =96=.

Barnacles, 8, 43, 245, =250=.

Bathymetrical division, 23.

=Bdelloura=, 160, =167=.

=B. Candida=, 160, =167=.

=B. rustica=, 160, =167=.

Beach-flea, 245, =289=.

Beak, 417.

=Bela=, 309.

Benthos, =23=.

=Beroïda=, 154, =157=.

Bilateral symmetry, 20, 302, =320=, 321.

Binomial nomenclature, 28.

=Bipinnaria=, 201.

Biramous, =243=, 257.

=Bittium=, 326, =374=.

=B. nigrum=, 326.

Bivalves, =306=, 307, 314, 315, 409.

Mud-boring, 452.

Rock-boring, 452, 460.

Blastostyles, =120=.

Blue crab, 275.

Blue-green seaweeds, 47, 48, 49.

Body-whorl, 304, =343=.

=Bolina=, 154, =156=.

=B. alata=, 154, =156=.

=B. septentrionalis=, 154, =156=.

=B. vitrea=, 154, =156=.

=Boltenia=, 473, =476=.

=B. clavata=, 473, =476=.

=Bopyridæ=, =292=.

Boreal, 23.

Boring amphipod, 290.

Boring-sponges, 105.

=Bostrychia=, 77, =89=.

=B. rivularis=, 77, =89=.

Botanical facts about algæ, =25=.

=Botryllus=, 473, =477=.

=B. gouldii=, 473, =477=.

=Bougainvillea=, =124=.

=B. superciliaris=, 116, =124=.

Box-crab, =287=.

=Brachyura=, 241, 258, =272=.

Brain-corals, 146.

Branchiæ, 302, =319=, 329, 336, =413=.

Dermal, 208.

=Branchiolaria=, 201.

=Brissopsis=, 217, =227=.

=B. lyrifera=, 217, =227=.

"Brit," =249=.

Brittle-stars, 43, 200, =214=.

Brown bodies, 190, =193=.

=Bryopsis=, 51, =59=.

=B. plumosa=, 51, =59=.

=Bryozoa=, =191=.

Buccal mass, 302, =317=.

=Buccinidæ=, 327, =391=.

=Buccinum=, 12, 309, 313, 327, 330, =392=.

=B. undatum=, 42, 44, 314, 327, 331, =392=.

=Bucidium parasiticum=, 144.

=Bugula=, 188, 192, 193, =195=.

=B. flabellata=, 188, =196=.

=B. Murrayana=, 188, =196=.

=B. turrita=, 43, 188, =195=.

=Bulla=, 324, =351=.

=B. nebulosa=, 324, =351=.

=B. occidentalis=, 324, =351=.

=B. solitaria=, 324.

=Bullidæ=, =324=.

Butterfly-shells, =323=.

=Byssus=, =415=, 426, 432.

C

=Caberea=, 188, =195=.

=C. Ellisii=, 188, =195=.

Cake-urchins, 218, =224=.

=Calappa=, 241, =287=.

=C. flamma=, 241, =287=.

=Calappidæ=, 241, =287=.

=Calcarea=, 100, =104=, =106=.

Calcareous hydroids, =129=.

Seaweeds, =31=, 147.

Californian province, =312=.

=Callinectes=, 241, =275=.

=C. hastatus=, 12, =275=.

=C. sapidus=, 241, 274, =275=.

=Calliostoma=, 312, 325, =361=.

=C. annulatum=, 325, =361=.

=C. canaliculatum=, 325, =361=.

=C. costatum=, 325, =361=.

=C. jujubinum=, 325, =361=.

=C. occidentale=, 325, =361=.

=Callista=, 311, 410.

=C. gigantea=, =450=.

=C. maculata=, =450=.

=Callithamnion=, 15, 78, 79, =90=.

=C. americanum=, 78, =90=.

=C. Baileyi=, 78, =91=.

=C. byssoideum=, 78, =91=.

=C. floccosum=, 78, =91=.

=C. Pylaisæi=, 78, =91=.

=C. seirospermum=, 78, =91=.

=Callophyllis=, 76, =82=.

=C. laciniata=, 76, =82=.

=C. variegata=, 76, =82=.

=Calothrix=, 48, =49=.

Cameo-cutting, =381=.

Campanularians, 116, 121, =125=.

Canal, 302.

Anterior, =344=.

Posterior, =344=.

System of sponge, 103.

=Cancellaria=, 310, 327, =402=.

=C. reticulata=, 327, =402=.

=Cancellariidæ=, 327, =402=.

=Cancellus=, =266=.

=Cancer=, 241, =277=.

=C. antennarius=, 241, =280=.

=C. borealis=, 241, =277=.

=C. irroratus=, 241, =277=.

=C. magister=, 241, =278=.

=C. productus=, 241, =278=.

=Cancroidæ=, 241, =277=.

=Caprella=, 8, 242, =291=.

=C. geometrica=, 242, =291=.

=Capulidæ=, 325, =369=.

Carapace, 243, =246=.

=Carcinides=, 241, =274=.

=C. mænas=, 241, =274=.

=Carcinus mænas=, 41, =274=.

=Cardiidæ=, 407, =453=.

=Cardita=, 406, =440=.

=C. borealis=, 406, =440=.

=C. floridana=, 406, =440=.

=Carditidæ=, 406, =439=.

=Cardium=, 310, 311, 407, 410, 413, =453=.

=C. corbis=, 407, =454=.

=C. elatum=, 407, =454=.

=C. islandicum=, 407, =454=.

=C. isocardia=, 407, =454=.

=C. lævigatum=, 407, =454=.

=C. magnum=, 407, =453=.

=C. mortoni=, 407, =454=.

=C. pinnulatum=, 407, =454=.

=C. quadrigenarium=, 407, =454=.

=C. serratum=, 407, =454=.

=C. substriatum=, 407, =454=.

Caribbean province, 310.

Carinated, 302.

Cartilage, =417=.

Cartilaginous, 27.

=Cassididæ=, 326, 380.

=Cassiopeia=, 133, =140=.

=C. frondosa=, 133, =140=.

=Cassis=, 310, 326, =380=.

=C. cameo=, 326, =380=.

=C. inflata=, 326, =381=.

=C. Madagascarensis=, =381=.

=C. testiculus=, 326, =381=.

=C. tuberosa=, 326, =380=.

=Caudina=, 228, =233=.

=C. arenata=, 228, =233=.

=Caulerpa=, 51, 56, =59=.

=C. Mexicana=, 51, =60=.

=C. paspaloides=, Plate VIII.

=C. plumaris=, Plate VIII.

=C. plumosa=, 51.

=C. prolifera=, 51, =60=.

=C. Wurdemanii=, 51.

=Caulerpaceæ=, 51, =59=.

=Cellepora=, 188, =197=.

=C. pumicosa=, 188, =197=.

=C. ramulosa=, 188, =197=.

=C. scabra=, 188, =197=.

=Cellularia=, 188, =195=.

=C. ternata=, 188, =195=.

=Cellularina=, 188.

=Cenobita=, 240, =268=.

=C. diogenes=, 240, =268=.

=Cenobitidæ=, 240, =268=.

Cephalic, 243, =246=.

=Cephalopoda=, 301, 315, 320, 321, =464=.

Cephalothorax, 243, =246=, 272.

=Ceramieæ=, 78, =90=.

=Ceramium=, 27, 43, 78, =92=.

=C. diaphanum=, 78, =93=.

=C. fastigiatum=, 78, =93=.

=C. rubrum=, 78, =92=.

=C. rubrum, var. proliferum=, 78, =93=.

=C. rubrum, var. secundatum=, 78, =93=.

=C. strictum=, 78, =93=.

=C. tenuissimum=, 78, =93=.

=C. tenuissimum, var. patentissimum=, 78, =93=.

=Cerata=, 353.

=Cerebratulus=, 160, =170=.

=C. angulatus=, 160, =170=.

=Cerianthus=, 144.

=Cerithidea=, 326, =375=.

=C. sacrata=, 326, =375=.

=C. scalariformis=, 326, =375=.

=Cerithiidæ=, 326, =373=.

=Cerithium=, 326, =374=.

=C. floridanum=, 326, =374=.

=C. minimum=, 326, =374=.

=C. muscarum=, 326, =374=.

=Cerostoma=, 326, =385=, 387.

=C. foliatum=, 326, =385=.

=C. nuttallii=, 326, =385=.

=Cestida=, 154, =157=.

=Cestoda=, =160=.

=Cestum=, 154, =157=.

=C. veneris=, 154, =157=.

=Cetochilus=, 239, =249=.

=Chætæ=, =173=.

=Chætangieæ=, 76, =80=.

=Chætobranchus=, 161, =182=.

=C. sanguineus=, 161, =182=.

=Chætomorpha=, 51, =53=.

=C. ærea=, 51, =53=.

=C. linum=, 51, =54=.

=C. melagonium=, 51, =53=.

=C. picquotiana=, =54=.

=C. tortuosa=, =53=.

=Chætopoda=, 161, =171=.

=Chalinopsilla=, 100, =107=.

=C. arbuscula=, 100, =107=.

=C. oculata=, 100, =107=.

=Chamædoris=, 51, =56=.

=C. annulata=, 51, =56=.

=Champia=, 77, =85=.

=C. parvula=, 77, =85=.

=Charybdæa=, 133, =137=.

=C. marsupialis=, 133, =137=.

=Cheilostomata=, 188, 194.

Chelæ, 243, =258=.

Cheliped, 243, =258=.

=Chelura=, 242, =290=.

=C. terebrans=, 13, 242, 290.

=Chicoreus rufus=, =382=.

=Chione=, 406, =451=.

=C. fluctifraga=, 406, =451=.

=C. simillima=, 406, =451=.

=C. succincta=, 406, =451=.

=Chiridotea=, 242, =294=.

=C. cæca=, 242, =294=.

=C. entomon=, 242, =294=.

=Chiton=, 9, 309, =322=.

=C. albus=, =323=.

=C. apiculatus=, =323=.

=C. ruber=, 41, =323=.

=C. spinosus=, =322=.

=Chitonidæ=, 312, 322.

=Chlorophyceæ=, 28, 47, 51.

=Chlorostoma=, 312, 325, =362=.

=C. brunneum=, 325, =362=.

=C. funebrale=, 325, =362=.

Choanocytes, =102=.

=Choanoflagellata=, 102.

=Chondria=, 77, =90=.

=C. dasyphylla=, 77, =90=.

=C. striolata=, 77, =90=.

=C. tenuissima=, 77, =90=.

=Chondrospongiæ=, 100.

=Chondrus=, 76, =80=.

=C. crispus=, 38, 76, =80=.

=Chorda=, 63, 68, =69=.

=C. filum=, 63, =69=.

=Chordaria=, 62, =67=.

=C. flagelliformis=, 43, 44, 62, =67=.

=Chordariaceæ=, 62, =67=.

=Chordata=, 19, 472, =474=.

=Chorus=, 312, 326, =388=.

=C. belcheri=, 326, =388=.

Chromatophores, =467=.

=Chrysodomus=, 12, 309, 313, 327, =392=.

=C. decemcostatus=, 327, =392=.

=Chylocladia=, 77, =85=.

=C. articulata=, 77, =85=.

=Cidaridæ=, 217, =222=.

=Cidaris=, 217, =222=.

=C. tribuloides=, 217, =222=.

Ciliary flames, 164.

Cinereous, 302.

=Cirolana=, 242, =292=.

=C. concharum=, 242, =292=.

=Cirratulidæ=, 161, =181=.

=Cirratulus=, 161, =181=.

=C. grandis=, 161, =181=.

Cirri, =172=, 302.

=Cirripedia=, 239, =250=.

Cirripeds, 251.

=Cistenides=, 162, =183=.

=C. Gouldii=, 162, =183=.

=Cladocera=, =238=.

=Cladophora=, 26, 51, =54=.

=C. arcta=, 51, =54=.

=C. gracilis=, 51, =54=.

=C. rupestris=, 51, =54=.

=Cladostephus=, 62, =65=.

=C. verticillatus=, 62, =65=.

Clam, 321, =448=.

Giant, 447.

Hard-shell, 448, 451, 456.

Little Neck, 410, 448.

Soft-shell, 456.

Worms, 176.

Classification, =19=.

Of gasteropods, =348=.

Of mollusks, =320=.

=Clava=, =122=.

=C. leptostyla=, 116, =122=.

=Clibanarius=, 240, =267=.

=C. vittatus=, 240, =267=.

=Cliona=, 100, =106=.

=C. sulphurea=, 100, 105, =106=.

=Cloaca=, =229=.

=Clymenella=, 162, =183=.

=C. torquata=, 162, =183=.

=Clypeaster=, 217, =224=.

=C. ravenellii=, 217, =224=.

=Clypeastroidea=, 217, =224=.

=Clytia=, =126=.

=C. bicophora=, 116, =126=.

=C. poterium=, 116, =126=.

Cockles, 453.

=Codiaceæ=, 51, =59=.

=Codium=, 51, =59=.

=C. tomentosum=, 51, =59=.

=C[oe]lenterata=, 111, 112, =113=.

=C[oe]lopleurus=, 217, =222=.

=C. floridanus=, 217, =222=.

C[oe]nosarc, 118.

Coffee-shells, 379.

Collecting, =6=.

And preserving seaweeds, =15=.

At Bar Harbor, =40=.

=Columbella=, 326, =388=.

=C. avara=, 326, =389=.

=C. corrugata=, 326, =389=.

=C. gausapata=, 326, =389=.

=C. lunata=, 326, =389=.

=C. mercatoria=, 326, =388=.

=C. similis=, 326, =389=.

=Columbellidæ=, 326, =388=.

Columella, 302, =344=.

=Comatula=, 234, =235=.

Comb-jellies, 112, 115, =155=.

Communal life, 121.

Conceptacles, =72=.

Conchs, =377=.

Conch-shell, =376=.

Concrescent, =302=.

=Confervaceæ=, 26, 51, =53=.

=Conidæ=, 327, =401=.

=Connostomæ=, =133=.

=Conus=, 313, 327, =401=.

=C. floridanus=, 327, =402=.

=C. gloria-maris=, 401.

=C. pealei=, 327, =402=.

=Copepoda=, 239, =249=.

=Corallina=, 29, 78, =96=.

=C. officinalis=, 41, 43, 78, =96=.

=C. rubrum=, 142, 146, =147=.

Coralline Crags, =192=.

Zone, 30, =31=.

=Corallineæ=, 78, =95=.

Corallite, =146=.

Corallum, =146=.

Corals, 112.

Cordate, =302=.

Cormophytes, 25.

=Cornacuspongiæ=, 100.

=Coronula diadema=, 255.

=Corymorpha pendula=, 116.

=Coryne=, 116, =123=.

=C. mirabilis=, 116, 123.

=Cosmocephala=, 160, =170=.

=C. ochracea=, 160, =170=.

=Costæ=, =302=.

Cowry-shell, =377=.

Crabe enragé, =274=.

Crabs, 244, 247, =272=.

Blue, 275.

Box-, 287.

Fiddler-, 241, 282.

Ghost-, 282.

Green, 274.

Hermit-, 264.

Kelp-, 286.

Lady-, 276.

Mud-, 281.

Oyster-, 287.

Purple shore-, 281.

Red, 278.

Rock-, 277, 280.

Sand-, 11, 241, 276, 282.

Sheep-, 285.

Shore-, 281.

Spider-, 241, 284.

Stone-, 280.

Swimming, 241, 274.

Toad-, 285.

Walking, 241.

Yellow shore-, 281.

=Crangon=, 240, =260=.

=C. franciscorum=, 240, =261=.

=C. vulgaris=, 240, =260=.

Crawfish, 240, 259, =261=.

Creeping Polyzoa, =193=.

Crenulated, 302.

=Crepidula=, 325, =369=.

=C. aculeata=, 325, =369=.

=C. adunca=, 370.

=C. fornicata=, 325, 369.

=C. navicelloides=, =370=.

=C. plana=, 325, =369=.

=C. rugosa=, =370=.

=Cribrella=, 204, 207, =211=.

=C. sanguinolenta=, 204, =211=.

Crimson Bluffs, 33.

=Crinoidea=, 200, =234=.

Crinoids, 202, 235.

Fossil, 235.

=Crisia=, 188, =194=.

=C. eburnea=, 188, =194=.

=Crossaster=, 204, =211=.

=C. papposus=, 204, =211=.

Crucibulum, 325, =370=.

=C. spinosum=, 325, =370=.

=C. striatum=, 325, =370=.

=Crustacea=, 238, =244=, 248, 257, 262.

=Cryptochiton=, =323=.

=C. stelleri=, =323=.

Cryptogams, 25.

=Cryptolithodes=, 240, 271.

=C. sitchensis=, 240, 271.

=Cryptonemiaceæ=, 78, 94.

=Cryptozonia=, 204, =211=.

Crystalline stylet, 302, =341=.

Ctenidia, 302.

=Ctenodiscus=, 204, =208=.

=C. corniculatus=, 204, =208=.

=Ctenophora=, 112, 115, 154, =155=.

=Ctenostomata=, 189, =197=.

=Cubomedusæ=, 133, =137=.

=Cucumaria crocea=, =231=.

=C. lævigata=, =231=.

=Cumacea=, 242, =288=.

=Cutleria=, 63, =71=.

=C. multifida=, 63, =71=.

=Cutleriaceæ=, 63, =71=.

Cuttlefishes, 44, 315, =467=.

=Cuvieria squamata=, =232=.

Cuvierian organs, =231=.

=Cyanea=, 133, 136, 138.

=C. arctica=, 44, 133, 138, =144=.

=C. fulva=, 133, =139=.

=C. versicolor=, 133, =139=.

=Cyanophyceæ=, 28, 48, =49=.

=Cyclomyaria=, 472.