L. litorea. This is supposed to be an importation from the Old World—to have come over by way of Iceland and Greenland, and then to have migrated down the Labrador coast. For many years Cape Cod formed a barrier to its advance, but now the species is abundant at Newport, and is reported at New York. It occurs on the Maine coast in astonishing numbers, living in vast colonies on the rocks exposed at low tide. The shell is thick, imperforate (no umbilicus), and usually has flat, spiral ribs. The columella is broad and white; the lip thin and black. The general color varies from black to olive or to dingy gray—sometimes reddish. The operculum is corneous, with the nucleus near the outer edge. Despite the variableness of this very common shell (the variations being chiefly in the height of the spire), it has certain unmistakable characteristics which, once seen, will enable the collector to determine it at once.
L. rudis. A smaller species than the last. It is strong and coarse, with revolving grooves and ribs, or smooth, with interrupted whitish bands and spots. A very common variety of this species is much smaller than the typical form, being about one sixth to one fourth of an inch long, smooth, with white and yellowish spots on olive. It clings to the rocks near high-tide mark, and is usually found attached to its resting-place by a bit of hardened mucus. While the typical L. rudis is heavy and banded, with a moderately high spire and no color, this [pg372] variety is thinner, with a higher spire and smoother surface, and has a color-scheme of decoration. It would be impossible to disconnect the two, for a large series of specimens will demonstrate beyond doubt, through every minute degree of variation, that the two forms belong to one and the same species. The station of L. rudis is much the same as that of L. litorea, but the smaller colored variety of rudis prefers quieter and more sheltered spots. It is occasionally found on reeds and grasses, on the piling of wharves, on large boulders above the line of algæ, and on algæ. It has been the writer's experience not to find rudis and litorea associated together.
| Littorina palliata. | Littorina irrorata. |
L. palliata. A low-spired, globular shell with a large, tumid, smooth body-whorl. The columella is flattened, curved below, and imperforate. The color is exceedingly variable, but is usually bright, shining olive, and this is especially the case with those individuals that find their station in the dense masses of algæ that form so conspicuous a feature of a low-tide scene on a rocky New England coast. From pure olive-green to yellow or bright red, with revolving black bands, seems a long chromatic leap, but it is not too great for the Designer of these pretty little globular shells. As a rule, the color of the shell simulates pretty closely that of the seaweed upon which it lives, and inexperienced eyes may easily overlook hundreds of specimens, all within close reach. The banded varieties are less common. The head of the animal is somewhat orange in color, the foot slate. The distinguishing features of this species are the smooth, globular shell, the low spire, the broadly flattened columella, and the orange-colored head of the animal. It is found on Fucus between tides, and often associated with L. rudis, on the whole coast north of New Jersey. The three preceding species are distinctly boreal in their range, but their place is taken in southern Atlantic waters of the United States by the following exceedingly common species:
L. irrorata. A solid, robust shell, which attains a length of about one inch. It is in many respects suggestive of L. litorea, its Northern relative, but the spire is higher, with straighter outlines, and the apex is acute. The surface is ornamented with closely set, revolving ribs; the sutures are indistinct; the lip is thin, though thickened just within; and the color is whitish to pale cinereous greenish, sometimes spotted with broken brownish lines. Within it is white, with a reddish tinge on the columella, and brownish spots on the edge of the lip. This species ranges from Maryland to Texas; its station is between tides.
L. angulifera. As the last species resembles L. litorea, so this other common Southern form resembles a greatly developed and large L. rudis of the smoother variety. It has a high-spired shell, with an acute black tip. It has about six whorls, which are variously decorated by wavy, oblique black lines and revolving black lines broken into series of dots and larger spots near the suture. The ground-color varies from yellow to purple. None of the colors are very vivid. Within it is yellowish-white. This species has a much thinner and more delicate shell than any of the littorinas thus far considered. It is common on the piling of wharves and in sheltered nooks everywhere [pg373] between tides. It is essentially a tropical species of very wide and extended range, but it does not occur north of St. Augustine. At Tampa it has been found in vast numbers. (Plate LXIX.)
The California coast furnishes two more species of Littorina. Their station is among the rocks between tides, and their habits are quite the same as those of the east-coast species.
L. scutulata. In this species the color is of various shades, generally dark gray, mottled with white spots. A good-sized specimen measures one half of an inch in length. The spire is high; the columella flattened, broad; the shell is purplish-white within the aperture. (Plate LXIX.)
L. planaxis. Somewhat larger than the last; wider; with a lower spire; grayish in color, sometimes speckled with white; chest nut-brown within. The columella is remarkably flattened, and a portion of the whorl next bordering the columella is excavated as though eaten away by the animal. These two species are often found associated on the rocks. (Plate LXIX.)
Genus Lacuna
Closely allied to Littorina is the genus Lacuna, one species of which, L. vincta, is very abundant on the New England coast. A curious and distinguishing feature of this genus is the umbilicus, which forms a lengthened groove along the columella. L. vincta rarely exceeds one half of an inch in length, and is thin, with a pointed spire of five whorls. It is either of a uniform horn-color, or purplish, or banded with chestnut. It may best be found upon marine plants in sheltered places, or may sometimes be gathered in quantity from the roots of Laminaria washed in by storms.
Genus Tectarius
The specific representatives of this genus are mostly tropical. T. nodulosus is abundant in Florida. It is about one half of an inch long, and has the flattened columella and round mouth characteristic of Littorina. It is decorated somewhat elaborately by revolving rows of nodules which cover the entire shell. Its station and habits are the same as those of Littorina.
Family CERITHIIDÆ
In this family we meet with a somewhat new type of shell—the long, turriculate shell, with many whorls and with a channeled [pg374] aperture. The Cerithiidæ include a large number of genera, mostly tropical in distribution. Their shells are usually highly ornamented in various schemes of sculpture, but they lack beauty in color. The animal is provided with a siphon, as is indicated by the anterior canal of the shell. The operculum is corneous, with a nearly central nucleus.
Genus Cerithium
C. floridanum. A very common species on the west coast of Florida, also sparingly found at Hatteras. It has eight or ten whorls, a gradually tapering spire, and a sharp apex; the aperture is oblong, with a deeply cut anterior canal projected to the left and backward (when the specimen is held apex up, with the aperture toward the observer). The sculpture is elaborate, consisting of many rows of revolving ribs, and close to the suture there are circling rows of nodes. There is a curious hump just to the left of the aperture, which is quite characteristic of the genus. The color is whitish-gray; the length one and a quarter to one and a half inches. Station, shallow water in lagoons and sheltered spots. (Plate LXIX.)
C. muscarum. Another Floridian species, somewhat smaller than the last (one inch in length). It has heavy, prominent, transverse ribs crossed by circling rows of chestnut spots, one heavy revolving rib around the base; eight or nine whorls; a high-tapering spire; and a sharp apex. The aperture is oblong, with the anterior canal projecting to the left. The columella is arched; the color shining gray to very light purplish. This very pretty little shell may be gathered literally by the shovelful all along the west Florida coast in sheltered spots, on sandy and shallow bottoms. (Plate LXIX.)
C. minimum. A still smaller Floridian shell, with jet-black aperture and anterior canal projecting horizontally to the left. The sculpture-plan is of revolving ribs and a series of white granules just below the sutures. Its station is the same as that of the last. Often the bottom of a lagoon will seem to be literally paved with these somber-hued little shells. From Tampa Bay to Charlotte Harbor they are very abundant.
Genera Bittium, Triforis
These are allied genera, having numerous species upon our coasts, but the shells are so small that the inexpert collector is not likely to notice them. Hosts of these minute, turreted, decussated, blackish shells are to be found on the wiry grasses of salt-marshes. They are also found on algæ at low-water mark. In Triforis the whorls turn to the left. Range from Cape Cod to South Carolina. [pg375]
Genus Cerithidea
C. scalariformis. This species has the suggestive outlines of the family, but the aperture is simpler. The outer lip is considerably thickened, sinuous, and yellow; there is a very slight notch at the angle of the columella, and the lip serves for an anterior canal. The apex is wanting by reason of the usual truncation of two or three whorls of the spire. There are revolving ribs on the base; longitudinal ribs elsewhere. The color is a dingy drab; within, brownish-yellow. It is found in brackish water in Georgia and Florida. This species is said to suspend itself from overhanging vegetation by means of glutinous filaments. It may remain out of water for an almost indefinite time. (Plate LXIX.)
C. sacrata. A species very common on the mud-flats of San Francisco Bay. It is a high-spired shell of ten heavily ribbed whorls, with a series of revolving ribs on the body-whorl. The outer lip is sinuous, and the columella is slightly twisted. It is nacreous and brown within, dingy blue-black without. Length one inch to an inch and a quarter. (Plate LXIX.)
Family VERMETIDÆ
Genus Vermicularia
V. spirata. This is a very curious creature when considered from the point of view of the gasteropod mollusk. It seems at first as though it would be better to regard it as a worm which had created for itself a calcareous covering. But it is a true prosobranch notwithstanding the fact that it has departed widely from the conventional design in the fashioning of its shell. At first the shell starts out in a regular form, and then the whorls become separated, finally wandering about in a seemingly aimless manner. The irregular prolongation sometimes measures ten inches in length. The animal is in no way remarkable except in having the viscera greatly elongated and the foot very short and broad. The color of the animal is light brown with black spots; the shell-color is rufous or ashy-white. Shells of this genus are often found grouped together in an inextricable mass. It is found in shallow water from New England to Florida.
Family STROMBIDÆ
This is a particularly interesting family, but it is tropical, and is represented on the shores of the United States by only one [pg376] genus, Strombus, of which we have but a few species. Strombus is a scavenger,—a buzzard among mollusks,—and its sense of smell is evidently very acute. Its eyes are much more highly developed than the usual gasteropod visual organs, and they are placed at the tip-ends of two very substantial eye-stalks or-pedicels. The tentacles are slender and project from the eye-pedicels. The foot is curiously developed; that portion of it which would naturally constitute the creeping-disk is exceedingly small, but the metapodium (the hinder part of the foot, upon which the operculum is situated) is very large. The corneous operculum upon its end, which is far too small to close the entrance of the shell when the creature retires within it, looks like a claw. Instead of creeping along the sand, Strombus proceeds by jumps or awkward leaps, turning its heavy shell first to one side, then to the other. The shell is usually heavy, with the outer lip greatly thickened.
Genus Strombus
S. pugilis. The very common Floridian species, often three to four inches in height, with a short spire covered with nodes or short, obtuse spines, which are also found upon the shoulder of the body-whorl (sometimes smooth). The aperture is long, with a wide notch in the outer lip and a posterior canal. Living specimens have a tough, leathery epidermis covering at least the body-whorl. The color is brownish. The columella is covered with a fairly thick callous deposit, and, as within the aperture, is highly polished, and deep purple, blackish-chestnut, or vivid carnation-red in color. The smoother varieties have gone under the name of S. alatus, but the identity of the two species is assured. This pugilistic Strombus is a very active mollusk, and when placed in a boat will sometimes effect its escape over the side in a most surprising manner. The species is very abundant in all the shallow waters of Florida. A piece of meat on a string, left overnight in some sheltered sandy spot where there are from six to eight feet of water, will surely attract them. In Florida, where the waters teem with life, unless the bait is protected in a wire cage, the chances are that the hosts of crustaceans and fish will make away with it long before the strombs can arrive on the scene. (Plate LXX.)
S. gigas. One of the largest of gasteropods, very common on the Florida Keys and also occurring in southern Florida. Hundreds of thousands of these shells have been sent to Europe from the Bahamas to be cut into cameos. This familiar shell is to be seen everywhere in the South, placed about flower-gardens and lining the paths and walks in yards. It is generally known in Florida and the West Indies as the "conch-shell." The animal is used as food in Key West, and is very generally eaten throughout the Bahamas. From their habit of eating [pg377] these animals the natives of some of the Bahama Islands are themselves called "Conchs." The rich pink color of the shell is very striking.
There are perhaps seventy-five or eighty species of Strombus inhabiting the tropical seas, and many of them are highly prized by collectors on account of their great beauty.
| PLATE LXIX. | |
|---|---|
| 1, Littorina angulifera, twice natural size. | 4, Cerithium floridanum. |
| 2, Littorina scutulata, much enlarged. | 5, Cerithium muscarum. |
| 3, Littorina planaxis, enlarged. | 6, Cerithidea scalariformis, enlarged. |
| 7, Cerithidea sacrata. | |
| PLATE LXX. | |
|---|---|
| 1, Strombus pugilis. | 3, Trivia pediculus. |
| 2, Cypræa exanthema. | 4, Trivia californica. |
| 5, Trivia quadripunctata. | |
Family CYPRÆIDÆ
Genus Cypræa
Cypræa is one of the "aristocratic" genera. Whether the shell or the animal itself is considered, there is probably no genus of mollusks which offers so much of beauty and interest to the collector and student. The genus is a tropical one, and finds its metropolis among the coral-fringed islands of the equatorial Pacific. Despite their brilliant colors and general attractiveness, the cowries—for such is their popular name—are very modest and shy; they prefer to hide among rocks, where they may be secure from molestation, for probably their conspicuous appearance is a real source of danger to them. In the animal of Cypræa the mantle is provided with two large lateral lobes, which are reflexed and meet over the top of the shell; thus, when the mantle is fully extended, the shell is entirely concealed. These mantle lobes are often furnished with numerous forked, tufted, or ramified filaments. The foot is long; there is no operculum. The color of the animal is often very striking in its intensity. A description of the cowry-shell is hardly necessary, so familiar is every one with it. A deposit of enamel is made all over the shell, and its painting and decoration, usually very elaborate, is reserved for the adult as a final process in the artistic completion of its home. The aperture is as long as the shell, is channeled at both ends, and is toothed along both margins. The spire is insignificant and is concealed by layers of enamel. In the young the shell has a very different appearance, resembling a sharp-lipped Oliva, and its scheme of coloration may be entirely different from that employed by the adult.
Among the Cypræidæ are many remarkable species. The splendid Cypræa aurantia, a native of the Fiji Islands, is one of the shells most sought after by enthusiastic collectors. The natives [pg378] learned its value long ago, and hold specimens of it at very substantial prices. It is worn as an ornament by chiefs and as a mark of distinction. The well-known C. moneta, also a native of the Pacific Islands, has been very extensively used as money throughout the South Seas and in Africa. There are many collectors of shells who confine their efforts almost exclusively to this and to one or two of the other "aristocratic" genera. From an esthetic point of view this is very natural, but biologically the less pretentious mollusks are quite as interesting.
Of the one hundred and fifty or more species in existence only three are to be found upon the Atlantic coast of the United States, and the chances are decidedly against the finding of any of them north of extreme southern Florida.
C. exanthema. A species not uncommon at Key West, where it may be seen slowly crawling about the mangrove roots near the water's edge. It attains a length of from four to six inches, and is so highly polished that a good specimen could be used as a mirror. In color it is shining, light chestnut, clouded with purple; the lips are a dark, very rich chestnut; over all are whitish spots which appear to shine forth from beneath the enamel. Lengthwise along the middle of the back is a zone of lighter color which reflects a purplish sheen. (Plate LXX.)
C. spurca. Another Floridian species, properly belonging to the West Indian fauna. It is not more than one half an inch long, and is white in color, but it is so thickly dotted with yellow spots upon the back that it would pass for a yellow shell. The base is pure white. The surface of the shell glistens in the light.
Genus Trivia
In the genus Trivia the shell is shaped in every way like that of Cypræa, but its surface is never smooth. In the middle of the back is a longitudinal groove, from which run transverse ribs, which continue around to and enter into the aperture. The shells are always small, never exceeding one half of an inch in length, and their color is generally reddish or brownish, passing to pink.
T. pediculus. A Floridian species, first described by the great naturalist Linnæus. Like most of the descriptions of the earlier naturalists, this is very short and inadequate, and would apply equally well to almost any Trivia. The color is rose-pink, with several large brownish splashes on the back. The spire is entirely hidden. It is found in shallow water in pools, and on the beach after storms. (Plate LXX.) [pg379]
T. quadripunctata. Much smaller than the preceding; rose-red, with four conspicuous reddish-brown dots on the back, two on each side of the median dorsal groove. Found in Florida. (Plate LXX.)
On the California coast are also several species of Trivia and one Cypræa, but they belong to the Southern California peninsula, and are not commonly found farther north than Santa Barbara. The cowry is called C. spadacea; it grows to a length of about two inches, is highly polished, with white base and sides, and is bright chestnut above. As is usual in the cypræas, the spire is covered with enamel.
T. californica. A species found at Monterey and thence south. It lacks the median dorsal groove, and has a whitish color-streak instead. The ribs are white, and the ground-color of the shell is dark brownish-red. These little shells, when found upon the beach, are called "coffee-shells," from their somewhat striking resemblance to the coffee-bean, being flat on one side and rounded upon the other, and otherwise resembling it in size and color. (Plate LXX.)
T. solandri. This species may be found at Santa Barbara and San Diego. It is twice as large as the last species, and has a very deep groove in the back and widely separated ribs. Color rose to brown. The groove on the back penetrates into the white portion of the shell.
Family DOLIIDÆ
This small family furnishes two conspicuously handsome species belonging to the genus Dolium, which range from Hatteras southward into the West Indies.
Genus Dolium
D. galea and D. perdix. The animal in both of these species has a relatively large foot, which spreads out while in the act of creeping and seems far too bulky ever to be withdrawn into the shell. It is square in front, and, bulging out far to each side, tapers to a blunt point behind. The most noticeable feature of the animal, however, is the great development of its proboscis, which is quite as long as the shell itself. The siphon is also long and is curved over the back of the shell. The operculum is wanting in adult specimens. The shell of D. galea sometimes attains a length of eight inches, with a diameter of about six inches; the other species is not quite so large. They are both ventricose, thin, inflated shells, with large body-whorls and crenulated lips. Both are slightly umbilicated and ornamented with revolving, regularly spaced ribs. The ribs of D. perdix are not so highly raised, but they are painted with light reddish-brown spots. D. galea is white, with a lower spire and deeply channeled sutures. (Plate LXXI.)
Genus Pyrula
P. papyratia. One of the commonest as well as one of the handsomest of American shells. It is a Floridian species, found in shallow water and on sandy bottoms. The animal greatly resembles that [pg380] of Dolium, except that it has two side-flaps, which, when extended, partially inclose the shell. The shell is thin, with an almost flat spire and a greatly enlarged body-whorl. The aperture is flaring, and is drawn out anteriorly into a tapering canal, which gives to the shell the outlines of a pear. The ornamentation is revolving, but not highly raised, and there are ribs with very distinct longitudinal lines of growth between. The color is pure white, or sometimes yellowish, with rufous spots; within it is golden. This attractive shell is usually from three to four inches in length, but is sometimes found considerably larger. (Plate LXXI.)
Family CASSIDIDÆ
Genus Cassis
The cassides, commonly known as the "helmet-shells," are carnivorous mollusks, which lead an active life in sandy stations, prowling about in search of bivalves, upon which they prey. They have a large siphon and a fairly large and extensible proboscis. The foot is broad and strong, being well adapted for plowing through the sand. The shell of Cassis is large, generally heavy and inflated, with a short spire and a short, recurved anterior canal. The lip is much thickened. Upon the Atlantic coast of North America there are four species of Cassis. They are all properly West Indian in their faunal relations, but have found lodgment on the American shore at various points. All of them have been taken in the neighborhood of Cape Hatteras, two of them in West Florida, and two in Texas.
C. tuberosa. A large, heavy shell, often from six to eight inches in length, with a flattened spire. The aperture is long and narrow, with large white teeth upon the outer lip, which is also greatly thickened. The columellar lip is ribbed. A heavy deposit of enamel to the left of the columellar lip gives the shell a triangular outline. A row of very large nodes upon the shoulder of the body-whorl and two rows of obsolete nodes below are characteristic features of this species. The color is light yellowish-brown suffused with pink. The aperture and the columellar callosity are flesh-tinted, with chestnut trimmings. The anterior canal is deep and recurved.
C. cameo. A species of about the same size as the last, but more ovate or ventricose in form. It is coarsely striated, with elevated growth-lines, and has circling rows of large, rib-like elevations, having sometimes nodes upon the body-whorl. The columella is conspicuously ribbed and greatly expanded. The outer lip is thickened, and has lamelliform teeth within. Flesh-colored; teeth white; purple-brown trimmings. A great many of these shells are sent yearly from Nassau [pg381] to Italy, where they are used in cameo-cutting. It is owing to the fact that the substance of these shells is deposited in layers of different colors that they are available for this purpose. There are about fifty species of helmet-shells, the one most valued for cameo-cutting being known as the black helmet, C. Madagascarensis.
C. testiculus. A species found outside of the West Indies only at Key West and at Hatteras, where the Gulf Stream has brought so many West Indian forms, and left them at the point where it takes its oblique course away from the shore. This pretty species is smaller than the others just described. It has a low, depressed spire; longitudinal ribs crossing wide, flat revolving ribs; a long, narrow aperture; and a reflexed and thickened outer lip, also toothed. The columella is thickened and ribbed. The anterior canal is recurved over the back of the shell, as is usual in the genus. The color is bluish, with dark spots. There are square black spots on the reflexed lip; the aperture is pink, and the teeth and columellar ribs white. This species is exceedingly common at Nassau, and plays havoc with the more slowly moving bivalves, which it devours. (Plate LXXI.)
C. inflata. Perhaps the commonest species of Cassis on our coast. It is reported to be common at Beaufort, South Carolina, yet it is not so frequently met with out of the West Indies as some earlier collectors would have us believe. Beach-worn specimens, however, are not unusual all along the Florida coast. It attains a size of from three to four inches, and is a rounded, globose, ventricose shell, with a higher spire than is usual in this genus. The surface is almost smooth, the series of revolving ribs being scarcely raised on the body-whorl. The lip is thickened and reflexed, with prominent lamelliform teeth which continue as internal ribs. The lower portion of the columella is calloused and roughly granulated. The color is bluish-white, glazed, with large square brown spots. The region of the aperture is pure white. The collector should not remain content with a specimen or two of the poor beach-worn shells of this species. In general, this advice applies to the collection of all specimens. One can get no idea of the sculpturing and painting of shells from dead and worn specimens. It is quality rather than quantity that makes an interesting cabinet. (Plate LXXI.)
Family MURICIDÆ
Subfamily MURICINÆ
It seems like making a long leap to pass suddenly from the Cassididæ to the Muricidæ. In the natural biological order, as it appears in our present state of knowledge, a host of families and genera intervene between these two. But they are omitted here, either because they do not conspicuously occur upon our own shores, or because they are free-swimming pelagic mollusks, which live only far out at sea and rarely are found on the beaches. The family Muricidæ is an exceedingly large one, including a [pg382] bewildering number of well-characterized genera. It has many representatives in every sea, but, as is apt to be the case, the finest and most striking species are tropical. The animal is not peculiar in any way, being altogether a conventional prosobranch gasteropod, with moderately long foot, and the usual tentacles placed upon a small head. There is a retractile proboscis, which suggests carnivorous habits. In reality the Muricidæ are perfect pirates among the Mollusca, attacking nearly every species they encounter, piercing its shell and devouring the unfortunate inhabitant. They live in rocky and gravelly places or about coral reefs. Their shells are seldom colored, except about the aperture. What the shells lack in color, however, they fully gain in oddness of form and in sculpturing. The anterior canal varies from a mere notch to an astonishingly long channel. The tendency to nodes, varices, spires, and varicose processes in general is a prominent feature of the family.
There are several genera, with numerous species, upon the east and west coasts of the United States, but we can do no more here than mention those which are very common.
Genus Murex
Of this tropical genus there are two Floridian species—M. rufus and M. pomum. The genus has been very extensively divided into subgenera, based upon shell-characters alone. Some of these subgenera are usually accepted at full generic value, and their substitution for the old, well-established name Murex is to be expected. These two Floridian species fall within different subgeneric lines, and the student who goes to a museum to compare his catch with the labeled specimens on exhibition will probably be puzzled to find his two murices named Chicoreus rufus and Phyllonotus pomum respectively. But for our purposes the name Murex will do well enough.
M. rufus. This species scarcely ever exceeds three inches in length. Its spire is moderately high, and the aperture is oblong-ovate, with a long, slightly curved, and almost completely inclosed anterior canal. Through the end of this the fleshy siphon projects in life. The shell is most extravagantly sculptured—so intricately that it is difficult to [pg383] describe it. Its most conspicuous feature is the large foliaceous varices which cross the whorls, projecting almost one fourth of an inch from the body of the shell. Between each of these varices is a large node. There is, besides all this, a system of pronounced revolving ribs which cross the varices and nodes, giving to the shell a greatly roughened appearance. The interior is bluish-white. The operculum is corneous, with a subterminal nucleus. Unfortunately, this really handsome shell is usually incrusted with coralline or calcareous matter, which must be removed with acid before a good idea of its appearance can be had. In color it is reddish-brown to dark chestnut on the varices. It is very common on the west coast of Florida, but rarer elsewhere. (Plate LXXII.)
| PLATE LXXII. | ||
|---|---|---|
| Murex rufus. | Murex pomum. | Ocinebra poulsoni, enlarged. |
| Pteronotus festivus. | Cerostoma foliatum. | Cerostoma nuttallii. |
M. pomum. A more abundant species, found all along the coast from Hatteras to Texas. It is not so elongated as the last, and its sculptural design is much less exaggerated. Between each of the varices are two nodules. The aperture is oblong-ovate, and the anterior canal is nearly closed and recurved toward the back. Revolving ribs cross the varices and nodules. The color is ashen, with chestnut tips upon the nodes and varices, and chestnut-colored patches about the aperture. The varices are simple and not foliaceous as in M. rufus; the shell is more globose. Length two to three inches. (Plate LXXII.)
M. (Phyllonotus) fulvescens. The largest of the American murices. It is not commonly found except in Texas.
Genus Trophon
T. clathratus. A fairly common shell of the Maine coast; although it belongs to a deeper zone than that of the tides, it is occasionally found after storms upon the shore. It is a small fusiform shell, with many prominent longitudinal ribs and a produced anterior canal. Trophon is a boreal genus, which finds the best conditions for life in the icy waters of Labrador and Greenland.
Genus Urosalpinx
The genus Urosalpinx is closely allied to Murex and Trophon. Several of its species are found on the east coast of the United States.
U. cinerea. This well-known species is regarded by Chesapeake and Long Island Sound oystermen much in the light of a plague. These active predaceous mollusks live upon bivalves, and preferably upon oysters. They bore a small round hole through the shell of their helpless victims, and then proceed to extract the succulent, fleshy animal from within. The oystermen call them by the suggestive name of "drill," and wage incessant warfare upon them. In some years these mollusks appear to go into partnership with the large starfish, Asterias, and the combination of the two can soon destroy any oyster-bed. The original home of this destructive little creature is presumed to be in Chesapeake [pg384] Bay, but the transplanting of oyster-spat thence to Long Island Sound has introduced the enemy at the same time. The species has a wide range from Florida to Cape Cod, and locally north of that point; in fact, it may be counted upon to appear wherever there are oyster-beds. The shell is dingy gray in color, and its whorls are crossed by a dozen or more rib-like undulations, and numerous revolving striæ. The anterior canal is produced, and is yellowish-brown within. Length under an inch.
Genus Eupleura
E. caudata. A curiously flattened shell which has close family connections with that last described. The peculiarly flat appearance is due to the fact that there is a rather wide varix upon each side of the shell. It is a small species, never more than an inch in length, dingy gray, with longitudinal undulations upon the whorls, and a long, narrow anterior canal and crenulated lip. The animal is white and yellow, and is notable for its activity. Found from Maine to Florida, about low-tide mark.
On the west coast of the United States occurs a striking development of a group of the Muricidæ of a curious foliaceous appearance, belonging to the genera Pteronotus, Ocinebra, and Cerostoma.
Genus Pteronotus
P. festivus. The shell is marked by three well-raised varices upon each whorl, which are reflexed backward; between each varix is a rounded knob. All is covered with numerous spiral lines of sculpture, which upon crossing the varices are frilled. The aperture is oval and white within; the anterior canal is entirely closed and is reflexed slightly over the back. Length two inches; color dingy white. Found on the southern coast of California. (Plate LXXII.)
Genus Ocinebra
O. poulsoni. This has the same dingy white color as the species last described. Its plan of sculpturing is somewhat different and consists of a series of rounded varices, about nine to a whorl, crossed by spiral lines. The anterior canal is open, and just within the white aperture, upon the inner side of the lip, is a series of five or six little round teeth. This species frequents the waters near San Diego, and sometimes grows to be two inches in length. (Plate LXXII.)
O. lurida. A much smaller species than the last, being not more than one half to three fourths of an inch in length. Very common at Monterey and in San Francisco Bay. It is strongly marked with spiral lines covering the longitudinal undulations usually found in this genus, but which are less prominently developed in this case.
There are several species of small ocinebras upon the California coast, but they are not easily determined without a more critical examination [pg385] than we are giving our specimens. They are O. interfossa, a small shell with deep spiral grooves, sharp varices, and deep sutures; and O. circumtexta, also small, but heavy, short-spired, with scalloped or crenulated outer lip.
Genus Cerostoma
C. nuttallii. A species belonging to the southern coast of California. It may be recognized at once by two prominent characters: first, a horn-like projection from near the base of the outer lip, and, second, the tumid varices alternating with rounded knobs. It has no spiral series of lines like those in Pteronotus festivus; and it has a row of five or six little teeth upon the inner side of the aperture, like those in Ocinebra poulsoni. The anterior canal is closed. It is about two inches long. (Plate LXXII.)
C. foliatum. A shell somewhat like the last, but almost twice as large, with heavy wing-like varices (three upon each whorl), made up of overlapping plaits. The knobs between the varices are much smaller, while the revolving ribs, though fewer in number than in most of these west-coast murices, are heavy and large. The aperture is oblong, the anterior canal closed. There is a "horn" near the base of the aperture, as in C. nuttallii, but no row of teeth upon the under side of the lip. The color is dingy white. (Plate LXXII.)
In the waters of Oregon and Washington there are a few trophons and other forms similar to the east-coast genera. These no doubt belong to the boreal and arctic faunal provinces, and have spread over both the Atlantic and Pacific northern regions.
Subfamily PURPURINÆ
This is considered a subfamily of the Muricidæ, and the group therefore bears the subfamily termination -inæ. There is no vital difference between it and the subfamily Muricinæ. The operculum in the Purpurinæ has a lateral nucleus instead of a subterminal one, but beyond this there are no essential differences. The shell of the purpuras is generally heavy and solid, being adapted to a life among rocks which are exposed to the beating of the surf. There is a lack of that extravagant sculptural design so characteristic of the true murices, most of the purpuras being comparatively smooth, in order, no doubt, that they may offer as little resistance as possible to the rushing, seething waters of exposed rocky shores.
The Purpurinæ, like some of the murices, when mutilated, exude a reddish-purple fluid. On account of this, the ancient Romans used to gather great quantities of certain Mediterranean forms belonging to these families, place them in large mortars, [pg386] and grind them up, shell and all. A garment dipped in the mixture and then exposed to the sun would receive a rich purple dye. This was the basis of the famous "Tyrian purple." The process was lost, and was rediscovered many centuries later, but it was long ago abandoned in favor of the far superior modern chemical dyes.
Genus Purpura