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very strong and foetid smell, as if garlic and asafoetida were mixed together.” (Phil. Trans, Abr. II. 826.)

We have inserted this account here, because the shell which is the subject of it may be more familiar to our readers under the Linnaean name of Buccinum Lapillus than of Purpura Lapillus, but it is properly arranged under the genus Purpura.

Fossil Bucci NA.

M. Deshayes in his tables makes the number of fossil (tertiary) species 95, and he records the following as both living and fossil (tertiary), Nassa not appearing as a genus in his list,-Buccina undatum, reticulatum, maculosum, mutabile, clathratum, meriteum, Desnoyersi, prismaticum, asperulum, musivum, inflatum, polygonum, D'Orbignii, Linnaei, politum, and five new species, the names of which are not given. Dr. Fitton in his ‘Stratigraphical and Local Distribution’ notes two species below the chalk, viz., B. angulatum and B. naticoide in the Portland stone (N. Wilts, S. Wilts, Bucks), and the last-named species in the Portland sand (Bucks). Mr. Lea notes one species (new), B. Sowerbii, in the Claiborne Beds, Alabama. He observes that of the genus 27 species, including Nassa, have been observed in Great Britain, several as low as the mountain limestone, but chiefly in the London clay and the crag. After repeating the number given by Deshayes, Mr. Lea says that the genus appears to be much more abundant in the upper formations. The Pliocene of the sub-apennines furnishes 27 species. Bourdeaux (Miocene) 21. Paris (Eocene) 9. In America, he adds, four species have been found, Mr. Say having described two from the older Pliocene, Maryland, and Mr. Conrad two from York Town, Vir. ginia, also older Pliocene.

NAssA.

Animal very much depressed, with a very large foot extending beyond the body on all sides, but especially in front, where it is large and angular, whilst posteriorly it is insensibly narrowed. For the rest like the animal of Purpura. Shell globular, oval or subturriculated; aperture oblong, notched anteriorly; right lip sharp-edged, often plaited within; columellar lip covered with a large callous plate, extending more or less far. Operculum horny.

Mr. Lea (Contributions to Geology) says, “I have not hesitated to separate this genus from Buccinum (although Lamarck united them after having made the division) because they certainly form a very natural group. Cuvier separates it, as M. de Blainville also does, into a sub-genus. M. de Blainville certainly makes one of his sections of Buccinum consist of the genus Nassa ; but Rang separates it decisively.

Geographical Distribution. There are many living species mostly from the warmer climates. A very small number belong to Europe.

Habits. uch like those of Buccinum. The species have been found on reefs, coral sand, sand, sandy mud, and under stones, at depths ranging from the surface to 15 fathoms.

Mr. Powys has lately described eight new species from Mr. Cuming's collection. Example. , Nassa nodifera. Locality. The Gallapagos Islands and the shores of Pananna.

Fossil Nass. E.

There are many fossil Nassae, as the reader must have collected from the notice of the genus among the fossil Buccina. Mr. Lea describes and figures a new species from Claiborne, and adds that Mr. Conrad has observed in the tertiary of Maryland four species, three of which have been described by Mr. Say, in a recent state, upon the American shores. The genus occurs among the Gosau fossils, and Dr. Fitton in his Stratigraphical Table records two species below the chalk, viz., N. costellata and N. lineata, both from Blackdown. + + Ampullaceous Entomostomata, or those whose shells are, in general, globular.

Harpa.

Animal with a large head, without a proboscis, having the mouth opened below; two anterior tentacula, conical and very much approximated, carrying the eyes upon an enlargement situated externally a little below the middle; foot large, furnished anteriorly with a sort of heel; siphon rather large and a little elongated; branchial pectinations

unequal, two in number; orifice of the oviduct at the entrance of the branchial cavity of the right side, orifice of the deferent canal at the extremity of a very voluminous excitatory organ; vent on the same side.

Shell oblong, more or less convex, generally rather delicate, enamelled, furnished with regular longitudinal ribs; spire a little elevated and pointed, the last whorl very large; aperture oval, elongated, widely notched anteriorly, the right lip with an external bourrelet, columella simple, o anteriorly. No operculum according to M. ReyInauld.

Shell of Harpa ventricosa, and animal crawling with its shell.

Geographical Distribution, Habits, &c.—The genus is found in the seas of warm climates, and is more especially abundant, at the Mauritius and the neighbouring islands, whence the finest of the more common species and the many-ribbed harps are procured. The animal is said to be of a rich vermilion red. The fishery is principally carried on at low water with a small rake, to which a net is attached, on sand-banks at night, and at sunrise when the harps are probably out upon their feed. They have been known to take the bait on the fishing lines laid for olives (Oliva). MM. Quoy and Gaimard, and, afterwards, M. Reynaud state, that the animal of the harp can, sometimes, when attacked by an enemy, disembarrass itself of the posterior part of the foot, and completely withdraw itself into the shell. M. Reynaud explains this phenomenon by giving his opinion that the transverse laceration which causes, in the movement of contraction exerted by the animal, the separation of the posterior part of the foot, arises from the resistance which that part, too voluminous to enter the shell after the animal, encounters from the edges of the shell. M. Rang observes, that though no operculum has been found, (and the animal appears to have been carefully examined,) he does not hesitate to leave the genus among those which are provided with one, because, in the first place, Harpa is similarly organised, and, in the next, if deprived of that appendage, it has, at least, the posterior part of the foot to take, in some sort, its place.

Authors generally make the number of living species eight, and of these the most precious, though lately greatly depressed in value, is the Many-ribbed Harp (Harpa imperialis.) . But some of the species are very difficult of definition, though others are well marked. The shells when in fine condition are great favourites with collectors, and, indeed, a drawer of fine harps in all the freshness of their beauty is a sight worth seeing. Care should be taken to keep them with their mouths downwards and from the sun and light, or their brilliant colours will soon fade.

Example, Harpa ventricosa. Locality, Mauritius, &c.

Fossil HARPs. Only two species are recorded, in the tertiary formation.

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Deshayes, in his tables, states the number of fossil (tertiary) species to be eight; and of these, two, viz., C. echinophora and C. Tyrrhena, he records as both living and fossil (tertiary).

Oniscia.

A genus separated from Cassidaria by Mr. G. B. Sowerby, and considered by him as having its place next to that genus in the natural system. It differs from Cassis in the canal not being suddenly reflected; but Mr. Sowerby states that he has seen Cassides which very nearly approach Oniscia in the form of the aperture, and in the short, scarcely reflected canal. He thinks that the genus is intermediate between Cassidaria and Cassis.

Shell oblong, subcylindrical, apex generally rather obtuse, spire short, sometimes very short; base rather acuminated; aperture longitudinal, elongated, extending at the base into a very short canal: outer lip thickened, is. ticulated within, and rather contracted in the centre; inner lip expanded and covered with granules (Sowerby). The outside of the shells is tuberculated, cancellated, or ribbed. : Of the animal, says Mr. Sowerby, “we know nothing; but there is every reason for believing it to be related to that of Cassis, and that it has an operculum, though we have never seen it.'

Habits.-Littoral. Found in coarse sand. S Three living species are recorded, one from the South

eas.

Example, Oniscia cancellata. (Sowerby's Genera, Oniscia, fig. 1, 2, adult; 3, young. N. B. the specimens figured were from Mr. Broderip's collection, now in the British Museum.)

Oniscia cancellata, adult.

Fossil ONIscia.

One fossil species only is recorded. It is figured by Mr. G. B. Sowerby from the Italian tertiary.

Cassis.

Animal said to resemble generally that of Purpura. Shell inclining to oval, convex, with a spire but little projecting, nearly flat; aperture oblique, long, and narrow, with the anterior canal very short and recurved towards the back; right lip thick, furnished with an external bourrelet, and toothed within; columellar lip callous, nearly straight, and marked nearly throughout its length with transverse long teeth. Operculum horny, very rudimentary. Geographical Distribution.—The genus occurs principally in very warm latitudes; two or three are said to be found in the Mediterranean. Habits.-The species have been found at depths ranging from five to eight fathoms on sands. Deshayes gives thirty as the number of living species. These are divided into two groups by Lamarck; the first consisting of those species whose spire is marked by bourrelets (C. cornuta, for example); and the second of those whose spire is without bourrelets (C. rufa, for example). De Blainville divides the species into two groups also; the first consisting of those whose aperture is long, and

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external lip nearly straight (C. tuberosa, for example); the

second of those whose aperture is suboval, and the external

lip excavated (C. flammea, for instance).” Example, Cassis tuberosa. Locality, West Indian Seas.

Shell of Cassis tuberosa, and animal, denuded, of Cassis sulcosa (dominished). Fossil CAssiDEs.

Deshayes, in his tables, states the number of fossil (tertiary) species to be fifteen, of which he records Cassides flammea, granulosa, crumena, saburon, bisulcata, and a new species, as both living and fossil (tertiary).

Ricinula.

Animal nearly entirely resembling those of Buccinum and Purpura. Mantle provided with a tube; foot much wider, and auriculated, as it were, anteriorly; head semilunar, with conical tentacula, supporting the eyes at the middle of their external surface; excitatory organ of the male very large, recurved in the branchial cavity. Such is De Blainville's description, who made his observation on “la Ricinule horrible,” Ricinula horrida. Shell oval or subglobular, thick, beset with points or tubercles, with a very short spire; aperture narrow, long, with a notch (which is sometimes subcaniliculated) anteriorly; right lip often digitated externally, and toothed within; the left lip callous and toothed or wrinkled. Operculum horny, oval, transverse, concentric. De Blainville describes the elements of the operculum as a little imbricated. Geographical Distribution.—De Blainville says that of nine species of this genus, all those whose locality is known come from the Indian Seas. Habits.-The species have been found on coral reefs and rocks. Deshayes, in his tables, gives the number of recent species as fourteen. De Blainville separates the species into three sections: the first consisting of those with an evident canal anteriorly and behind the aperture (en arrière de l'ouverture) Ricinula digitata; the second of those without a canal and beset with spines, R. horrida; and the third of those without a canal and tuberculous, R. morus. He observes that this genus is evidently artificial: thus it contains one species which is a true Murer, whilst others are closely approximated to certain species of Turbinella; in fact, they have two or three plaits on the columella; finally, some of them scarcely differ, he says, from the true Pur

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Ricinula horrida

Fossil Ricinulae.

De Blainville and Rang both say that there is no fossil Ricinula. Deshayes, in his tables, records one, a new species, in the tertiary formations. (Bourdeaux, Dax, Turin.) Cancellaria. Animal said to resemble generally that of Purpura. Shell oval or globular, rather convex, reticulated, thick, with a spire slightly elevated and pointed; aperture demioval, notched or ...' anteriorly; right lip sharp-edged, striated within; columella nearly straight, with many well defined plaits. Operculum horny. Geographical Distribution.—The species are all exotic, and the inhabitants of warm seas. The localities of the bulk of those known are said by De Blainville to be inhabitants of the Indian and African seas (but see below). Habits.-The species have been found on sandy bottoms, at a depth ranging from seven to sixteen fathoms. De Blainville speaks of twelve recent species. He observes that the genus as adopted by him is not entirely the same as that of Lamarck, who gives that number. De Blainville withdraws from the genus the species whose aperture is evidently caniliculated, such as C. senticosa, which, as it appears to him, ought to remain among the Murices or the turriculated Turbinellae. Deshayes, in his tables, makes the number of living species thirteen. Mr. G. B. Sowerby (‘Zool. Proc.,’ 1832) describes twenty-two new species from the collection of Mr. Cuming, most of them from the warm latitudes of the Pacific side of South America. One of them, C. uniplicata, dredged in sand near Panama at a depth of ten fathoms, is the only species known to Mr. Sowerby with a single fold on the columella. Example, Cancellaria reticulata. Locality, Southern Atlantic Ocean (Lamarck).

Cancellaria reticulata.

FossiL CANcellARIAE.

Lamarck records seven fossil species. Rang says there are a good number. De Blainville observes that, according to Defrance, there are twenty species, two of which are identical, one from Italy, the other from Grignon, and one analogue from Italy. Deshayes makes the number of fossil (tertiary) species forty-two, one of which he notes as both living and fossil (tertiary). Mr. Lea describes and figures, in addition, eight species from the tertiary, formation of Alabama (Claiborne). He observes that the genus has been observed in England only in the London clay, from whence three species have been described; and, referring to Deshayes’ Tables and his forty-two species, remarks that sixteen are from the Subapennines (Pliocene), twelye from

Wol. IX—3 N

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Bourdeaux (Miocene), and five from Paris (Eocene). In America, he observes, a single species only, C. lunata (Conrad), had been theretofore observed. It was from the tertiary beds of Saint Mary's. Purpura.

Animal rather elongated, widened in front; head large with a very short proboscis; two tentacula, generally in front and approximated, conical, and supporting the eyes on an enlargement situated at the middle of their external part; mouth below, nearly always hidden by the foot, which is rather large, very much advanced and bilobated, as it were, anteriorly; branchial pectinations two, unequal; orifice of the oviduct at the entrance of the bran: chial cavity on the right side; orifice of the deferent canal at the right side of the neck, at the extremity of the exciting organ, which is generally voluminous; vent on the same side.

Shell of Purpura Persica, and animal of Purpura haemostoma.

Shell oval, thick, unarmed or tubercular, with a short spire, the last whorl larger than all the others together; aperture very much dilated, of an oval form, terminated anteriorly by an oblique notch; columella flattened, finishing in a point anteriorly; right lip sharp-edged, often thickened and furrowed internally, or strongly armed anteriorly with a conical point. Operculum horny, demicircular, the summit posterior. Geographical Distribution.—The form is widely distributed, but the number of European species is very small; the greatest development takes place in warm seas where the species are most abundant, particularly in South America. Habits.—The larger proportion of the species of this enus are hittoral. The true Purpurao have been found at epths ranging from the surface to twenty-five fathoms, and the division which forms the genus Monoceros, generally on rocks, at depths ranging from the surface to seven fathoms. De Blainville states that there are fifty living species of ordinary Purpurae, of which four only belong to the French seas. The species of Monoceros, he states, to be five; all from South America. Deshayes, in his tables, gives seventysix as the number of living species of the genus Purpura (Lam.), and six as that of the living species of Monoceros. Mr. Lea states that his cabinet has nine. We are not sure whether M. Deshayes includes among his seventy-six species P. granatina, P. squamigera, and P. squamosa, described by him. Mr. Broderip describes two new species, and Mr. Powys one, from Mr. Cuming's collection (Port St. Elena, Valparaiso, and Maldon Island, in the Pacific), and Mr. Broderip another, Purpura Gravesii, figured under the name of Murea cariniferus, in Mr. Sowerby's Conchological Illustrations. (Zoot. Proc.) Mr. Sowerby describes nine species of Monoceros, among them, M. punctulatum (Gray), from Mr. Cuming's collection. De Blainville divides the species into four sections:–1st. *hose whose right lip, near the notch, is armed with a tonical horn, or tooth, which is pointed, and more or less curved. This section is the genus Monoceros (De Montfort), the animal of which, according to M. Rang and others, differs in nothing from that of the other Purpurao., 2nd. The Buccinóid Purpurae, whose lip is without a tooth, and whose aperture is moderately widened. Purpura, Lapillus

(Buccinum Lapillus, Linn.) for example. (See above, Buccinum.) 3rd. The Patulous Purpurae also without a tooth at the lip, and whose aperture is very wide; Purpura Persica for instance. 4th. The ventricose tuberculated species, of which he gives P. meritoides as the type. M. Rang divides the species into two groups only. e first, consisting of those which have the right lip simple, or only furrowed internally: the second, of those whose right lip is always thickened and armed anteriorly with a conical point. Example of the first, Purpura Persica. Locality, East Indian Seas. Example of the second, Purpura imbricata (Monoceres imbricatum, Lam.). Locality, South America.

Purpura imbricata, Monoceros imbricatum.

Fossil, PURPURAE.

De Blainville states (Malacologie) that no fossil species of Monoceros were then known. Deshayes, in his tables, records one (tertiary) from Italy. Mr. Lea describes and figures three new fossil species from the tertiary of Claiborne, Alabama (Eocene of Lyell). Of the ordinary Purpura, De Blainville states that there are nine fossil species, one of which is the analogue of P. Lapillus (Buccinum Lapillus, Linn.), so common on our coasts, as well as those of France. Deshayes, in his tables, gives the number of fossil (tertiary) species as four, of which he records one, P. haemastoma, as both living and fossil.

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De Blainville speaks of the animal as entirely unknown; but according to Lesson, it resembles that of Purpura. Shell thick, rude, and wrinkled transversely on its external surface; spire very small, hardly projecting; aperture oval. very large, notched anteriorly, where there are two dentiform appendages; no columella; muscular impression of a horse-shoe shape, and very visible. Operculum horny, transparent, trapezoidal, concentric, with a marginal summit. Geographical Distribution.—South America is thé locality of Concholepas. It is very abundant on the coasts of Peru and Chile, and sometimes attains to a very large size. Habits.-Concholepas is, as yet, only known as a littoral species. Lamarck first placed Concholepas near Purpura. Cuvier gives it very nearly the same position. M. Rang remarks

that he might have well united the genus to Purpura, after

the example of De Férussac. In fact, he adds, M. Lesson's communication touching the animal which the latter brought home from the South Sea had proved to M. Rang that it differs in nothing from that of Purpura; its operculum alone affords a well-defined character. There is but one species known; but M. Rang states that there are two distinct varieties. Example, Concholepas Peruviana. Concholepas is not known in a fossil state, properly so called. It occurs among other species of the coast, at con

siderable clevations above the sea

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Concholepas Peruviana.

ENTOMO'STRACA (Müller). Shell Insects; for such is the meaning of the term applied to certain aquatic animals forming, according to Latreille and others, the second eneral division of the crustaceans, and for the most part inhabiting the fresh water. The brain, or rather the nervous knots which supply its place, consists of one or two globules merely. The heart is in the form of a long vessel. The branchiae, composed of hair-like processes, which are either isolated, or connected in a beard-like form, a pectinated shape, or one resembling aigrettes, form a portion of the feet, or of a certain number among them, and sometimes mandibles and the upper jaws. [CYPRIs, vol. v. p. 341.] Hence the term BRANCHIopoda. [See the title, vol. v. p. 338..] The number of the feet varies, and in some of the genera is above a hundred. These feet, ordinarily, are proper for no purpose but swimming; and are sometimes ramified or divided, and sometimes furnished with pinnules, or composed of lamellar joints. Nearly all of them have a shell, consisting of from one to two pieces, very delicate, and most frequently almost membranous and transparent, or at least a large anterior thoracic segment, often confounded with the head and appearing to replace the shell. The integuments are generally rather horny than calcareous, a condition which, as Latreille remarks, approximates the Entomostracans to the Insects and Arachnids. In those which are provided with ordinary jaws, the inferior or external ones are always uncovered, all the jaw-feet (pieds-mâchoires) performing the office of true feet, and none of them being applied upon the mouth. The second jaws, with the exception of the Phyllopoda, resemble those organs, and Jurine has sometimes designated them under the name of hands. These characters, says Latreille, distinguish the masticating Entomostraca (Entomostracés Broyeurs) from the Malacostraca; the other Entomostraca which compose his order Paecilopoda cannot, he says, be confounded with the Malacostraca, because they are deprived of organs fit for mastication, or because those parts which appear to perform the office of jaws are not collected anteriorly and preceded by a labrum as in the true crustacea and the masticating insects (insectes broyeurs), but simply formed by the haunches of the locomotive organs, and furnished, for the purpose of enabling them to execute that office, with small spines. The Poecilopoda, he observes, represent in this class those of the class of insects which are denominated suctorial (suceurs). They are almost all parasites, and seem to lead us by degrees (par nuances) or shades of difference to the Lernatae; but the presence of eyes, the property of moulting or changing the skin, or even of undergoing a metamorphosis, and the faculty of being able to transport themselves from one place to another by means of feet, appear to Latreille to establish a well-defined line of demarcation between the animals last named and the preceding. With regard to the metamorphosis, he remarks, that the young of the Daphnia, and of some other nearly allied genera, those probably also of Cypris and of Cytherina, differ not at all or scarcely at all from their parents, in point of form, at the time of their exclusion from the egg; but the young of Cyclops, of the Phyllopoda, and of Argulus, undergo in their infancy remarkable changes, as well in the form of the body, as in the number of feet. These organs, indeed, in some (in the Arguli for instance) suffer transformations which modify their uses. The same author states that he has consulted, relative to these transformations, several well-informed naturalists, who have had frequent occasion to observe the Lernaea, and that those observers had never seen a Lernara change its skin. The antennae of the Entomostraca, the form and number of which vary much, serve in many for swimming. The

eyes are very rarely placed upon a pedicle, and when they are so placed, the pedicle is no more than a lateral prolongation of the head, and is never articulated at its base. The last-named organs are often very much approximated, and even compose one only. The tail is never terminated by a fan-shaped fin, and never presents the false feet of the Malacostraca. The eggs are collected under the back, or external, and under a common envelope, having the form of one or two small groups situated at the base of the tail. They possess the power of preserving their vitality for a long time in a state of desiccation. [BINoculus, vol. iv. p. 410.] It would appear that not less than three moults are undergone by many of these animals before they become adult and capable of propagating their species, and it has been proved, in the case of some of them, that a single copulation will fecundate many successive generations. [BRANCHIopoda, vol. v. p. 342.]

In M. Latreille's second method, the Entomostraca were treated as a sub-class, with the following characters:—Mandibles naked or none; mouth formed of two rows of pieces; antennae and feet of a branchial form; tarsi without a horny nail at the end; shell clypeaceous or shieldlike, univalve or bivalve, or with annular horny or membranous segments of the body; eyes sessile, often united so as to form one.

1st Section. (Operculés, shell univalve or bivalve.) + Shell univalve. (Clypeacés.) 1st order, Xyphosures. (Example, Limulus.) 2nd order, Pneumonures (Ex. Ozolus.)

3rd order, Phyllopodes. (Ex. Apus.) +

Shell bivalve. (Ostrachodes.) 4th order, Ostrachodes. (Ex. Cypris.)

2nd Section. (Nues, body annulated throughout its length.) 5th order, Pseudopodes. (Ex. Cyclops.) 6th order, Cephalotes. (Ex. Polyphemus.)

In the last edition of Cuvier's ‘Régne Animal’ M. Latreille divides the Entomostraca into two orders. I. BRANCHIoPopA. (See that title, vol. v., p. 338.) II. Poecilopod A.” The Poecilopod A he divides into two families. 1st. Xyphosura. This family consists but of one genus, viz., Limulus. 2nd. Siphonostoma. This family he separates into two tribes. - 1. Caligides. This tribe contains the genera Argulus, Caligus, and its sub-genera Pandarus, Dinemoura, &c., and Cecrops. 2. Lernaeiformes. This tribe consists of Dichelestium and Nicothoe.

M. Milne Edwards remarks, that at the first glance the branchial feet of Apus and of many other Entomostraca would appear to have hardly anything in common with the ambulafory feet or buccal members of the Decapods; but, nevertheless, the same parts are found among the former. In fact, he observes, in the great foliaceous laminae or blades, the structure of which seems as complicated as it is anomalous, the analogues of the flagrum (fouet), palp, and stem (tige) are easily traced. The first of these appendages constitutes the flattened vesicle which occupies the basilary and external part of the foot: its form is the same as among the Stomapods, and its structure further confirms the approximation.

The last-named author proposes the following method, differing from that of Latreille not only in the number of the orders under which the different Crustacea are arranged, but also in the limits assigned to many of those divisions —

A Mouth deprived of special organs of mastication. Orders. Xyphosures. Siphonostomes. B Mouth armed with special organs of mastication, viz., with one pair of mandibles, and with one or more pairs of jaws.

• The reader win find those Poecilopoda, which are not already noticed in this work, either under that title, or under their generic names.

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