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Animal generally resembling that of Purpura. Shell delicate, nearly globular, ventricose, furrowed transversely; spire but little elevated, pointed, the last whorl forming nearly the whole of the shell; aperture large, oval, right lip undulated; columella often twisted, operculum horny. Geographical Distribution.-The seas of warm climates, especially those of India. One species, Dolium galea, inhabits the Mediterranean. The species are often found on reefs, some of them are very large. Seven seems to be the greatest number hitherto recorded, and Cuvier has separated the species into two sections, viz.: The Tuns (Dolium) and the Partridge Tuns (Perdix of De Montfort). Examples, Dolium galea, and Dolium perdix.

Geographical Distribution.-The seas of comparatively warm climates. Lamarck gives the Mediterranean as the locality of two species. Rang states that only one species is European. De Blainville speaks of the genus as inhabiting all seas except that of the North. The number of living species recorded appears to be

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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, denticulated 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.

Three living species are recorded, one from the South Seas.

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.)

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Shell of Dolium Galea, and animal denuded (diminished).
FOSSIL DOLIA.

Deshayes gives but one fossil (tertiary) species, and that (D. pomum ?) he gives doubtingly, placing it in the column headed species found both living and fossil (tertiary).' De Blainville alludes to four fossil species, two of which are analogues, according to Brocchi.

Cassidaria.

Animal supposed to bear a general resemblance to that of Buccinum and Purpura. Shell ovoid, ventricose, with the spire but little elevated; aperture long, rather narrow, with the anterior canal recurved; right lip furnished with a bourrelet; columellar lip covered by a large callosity, often granulous or wrinkled. Operculum horny.

Cassidaria echinophora.

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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Shell of Cassis tuberosa, and animal, denuded, of Cassis sulcosa (diminished). 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. Blainville describes the elements of the operculum as a little imbricated.

De

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 Murex, 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 Purpura.

Example, Ricinula horrida.

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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 subcaniliculated 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 Turbinella. 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 CANCELLARIA.

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), twelve from VOL. IX-3 N

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Bourdeaux (Miocene), and five from Paris (Eocene). In | (Buccinum Lapillus, Linn.) for example. (See above, BucAmerica, he observes, a single species only, C. lunata (Con- cinum.) 3rd. The Patulous Purpure also without a tooth at rad), had been theretofore observed. It was from the ter- the lip, and whose aperture is very wide; Purpura Persica tiary beds of Saint Mary's. for instance. 4th. The ventricose tuberculated species, of which he gives P. neritöides as the type. M. Rang divides those which have the right lip simple, or only furrowed the species into two groups only. The first, consisting of internally: the second, of those whose right lip is always thickened and armed anteriorly with a conical point.

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.

Example of the first, Purpura Persica. Locality, East Indian Seas.

Example of the second, Purpura imbricata (Monoceros imbricatum, Lam.). Locality, South America.

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Shell of Purpura Persica, and animal of Purpura hæmostoma.

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.

Purpura imbricata, Monoceros imbricatum.
FOSSIL PURPURE.

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. hæmastoma, as both living and fossil.

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Patelloid Entomostoma; that is, one whose shell is very large in its totality, very flattened, with a spire but little marked, and without a columella.

Concholepas.

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.

Habits.-The larger proportion of the species of this genus are littoral. The true Purpure have been found at depths 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 Purpura, 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. Lamarck first placed Concholepas near Purpura. Cuvier Broderip another, Purpura Gravesii, figured under the gives it very nearly the same position. M. Rang remarks name of Murex cariniferus, in Mr. Sowerby's Concholo-that he might have well united the genus to Purpura, after gical Illustrations. (Zool. Proc.) Mr. Sowerby describes the example of De Férussac. In fact, he adds, M. Lesnine species of Monoceros, among them, M. punctulatum son's communication touching the animal which the latter (Gray), from Mr. Cuming's collection. brought home from the South Sea had proved to M. Rang that it differs in nothing from that of Purpura; its oper culum alone affords a well-defined character.

De Blainville divides the species into four sections:-1st. Those whose right lip, near the notch, is armed with a Lonical 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 Purpuræ. 2nd. The Buccinoid Purpura, whose lip is without a tooth, and whose aperture is moderately widened. Purpura Lapillus

Geographical Distribution.-South America is the 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.

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 considerable elevations above the sea

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 general 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 branchiæ, 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 Pacilopoda 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 Lernææ; 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 Cythe rina, 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 Lernce, and that those observers had never seen a Lernca change its skin. The antennæ 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; antennæ 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.)

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Shell univalve. (Clypeacés.)

1st order, Xyphosures. (Example, Limulus.) 2nd order, Pneumonures (Ex. Ozolus.) 3rd order, Phyllopodes. (Ex. A pus.)

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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 Règne Animal' M. Latreille divides the Entomostraca into two orders.

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I. BRANCHIOPODA. (See that title, vol. v., p. 338.)
II. POCILOPODA.*

The PECILOPODA 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. Lernæiformes.

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 ambulatory 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 laminæ 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 will find those Poecilopoda, which are not already noticed in this work, either under that title, or under their generic names.

Orders.
Ostrapodes.
Cladocères.

Phyllopodes.

Copépodes.

Læmipodes.

Isopodes.
Amphipodes.
Stomapodes.
Decapodes.

According to the derivation of the word Entozoa, and the definition which we have given of it, this term should include every living creature found in the body of another (which has not been introduced from without): therefore the small microscopic animalcules detected in the semen of animals, called Spermatozoa, come under this head; and in a very able paper on the entozoa by Mr. Owen, we find them placed accordingly in this class, only situated in a separate group, denominated Protelmintho, and divided from the animals forming the class entozoa of Rudolphi. These M. Milne Edwards further states that Latreille, a little minute beings, which, from their size and organization, before his death, was again occupied with the subject, and rank with the assemblage of animalcules which are colintroduced into his method many modifications, which made lected under the head Infusoria in the Règne Animal,' it approach nearly to that proposed by M. Milne Edwards. have been detected in the secretion of the testicles of variThe latter says that Latreille in fact admitted into the class ous mammiferous animals arrived at maturity. When a Crustacea 12 orders, viz., the Decapods, the Stomapods, the drop of the secretion is expressed from a divided vas defeLæmipods, the Amphipods, the Isopods, the Dicladopods, rens shortly after death, and examined with a microscope, the Lophyropes, the Ostrapods, the Xyphosures, and the after being diluted with water, it is seen to be filled with • Siphonostomes; and that the Dicladopods very nearly corre- minute beings resembling tadpoles, and swimming about in spond to the Copepods of M. Milne Edwards. The last-named various directions, with different degrees of velocity, guided author, when speaking of Latreille's classification in the by the inflection of a slender tail. It has been doubted first edition of the 'Règne Animal,' speaks of Latreille's whether these are animated beings at all, or are to be connot attaching to the distinction of Malacostraca and Ento-sidered as analogous to the moving filaments of the pollen mostraca an importance which those divisions do not de- of plants; but leaving this undecided, we may proceed to serve; but M. Milne Edwards still retains the term Ento- state that the body is always of a compressed form, which mostraca; for we find in his synoptical table (Histoire Na- will distinguish these animalcules from the vegetable infuturelle des Crustacés-Suites à Buffon), under the sub- soria, in which the body is always ovoid or rounded. With class of Maxillated Crustaceans, the legion of Branchio-regard to their organization, no alimentary canal or gastric pods, containing the orders Ostrapoda and Phyllopoda, and the legion of Entomostraca, consisting of the orders Copepoda and Cladocera.

The reader who wishes to study the classification, economy, and anatomy of the Entomostraca, should more particularly consult, besides the works above alluded to, those of Swammerdam, Needham, Leuwenhoek, De Geer, Ramdhor, Schoeffer, Straus, Hermann, the younger Fabricius, the Jurines. father and son, Adolphe Brongniart, Slabber, Desmarest, De Blainville, Thompson, and Audouin. ENTOZO'A (from the Greek words entos (¿vròç), within, and zoon (ov) an animal). Under this name are designated the different living beings which are produced and developed within other living beings. It comprehends a series of animals differing greatly from one another in form and organization, and having but one character in common; which is, that they are all parasitic, or have their exclusive habitation in, and live at the expense of the bodies of other animals. They can scarcely be said to form a distinct class in the animal kingdom, some of the species being closely resembled both in external appearances and internal structure, by individuals placed in other classes, and only differing from them in the localities where they are found; thus the zoosperms, or seminal animalcules, which are enumerated by some zoologists with the entozoa, closely resemble the true cercariae of vegetable infusions.

Entozoa are found in most animals; they have been discovered in all the mammalia from man down to the cetacea; they also occur in the other classes of the vertebrata; indeed, it seems that a greater number reside in birds, reptiles, and fishes than in mammals. The invertebrata have also their peculiar parasites; and they have been ascertained to exist in all the insect tribes, and in beings still lower in the scale. The best known species are those which inhabit the intestines of the human subject, and vulgarly go by the denomination of worms, which term was probably derived from the resemblance which the Ascaris lumbricoides bears to the common earth-worm, as this species is most frequently met with, and was the first described of the human entozoa, being mentioned by Hippocrates, who called it the ἕλμινς στρογγύλος, or round worm.

A short list of the different kinds of worms found in the human intestinal canal, with an enumeration of their causes, the morbid symptoms which they occasion, and the mode of treatment, are given under the article ANTHELMIN

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cavities have been detected, nor organs of generation; they are said to be fissiparous, the body and tail spontaneously dividing, and forming two independent beings. The shape of these zoosperms differs in different animals, the large end, or body, being bigger in proportion to the tail in some than in others, and their size not being always in relation to that of the animal to which they belong: thus those of the rabbit are nearly as large as those from the bull. That these animalcules perform some office in the economy of nature seems probable from the fact that in those animals which are subject to periodical sexual development, as the hedgehog and mole (in which the testes undergo an alteration in size in different seasons), these creatures are not found during the period of quiescence, or partial atrophy of the glands; neither do they exist in the seminal passages before the age of puberty. But the part in the physiology of generation which these zoosperms perform is not so clear. The spermatozoa have been detected in the other orders of the vertebrate and in the articulate animals.

In the present group are also included those minute internal parasites which have been detected in the bodies of many of the entozoa themselves, and which, from their external form, are referrible to the infusoria.

The Trichina Spiralis, an entozoon, found inhabiting the muscles of the human subject, has been placed by Mr. Owen, who first described it, with the preceding animalcules; but further observations on its organization have discovered a complexity of structure which qualifies it to occupy a place in the highest instead of the lowest group into which the present class of animals is divided.

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We now proceed to the more legitimate part of our subject, viz. the true parasites forming the class Entozoa of Rudolphi, and it is first necessary to arrange them according to some classification. Availing himself of the difference in their internal organization, Cuvier divided them into the cavitaires,' or those which have an abdominal cavity, and a distinct intestinal canal within it, and the parenchymateux,' or those in which no intestinal tube is traceable, and which for the most part cousist throughout of an homogeneous structure; but this classification is any thing but a natural one, as worms the most dissimilar in their general appearance are here promiscuously congregated together. Mr. Owen, in the article which we have before alluded to (in the Cycloped. of Anat.), has adopted the arrangement of Cuvier, only inventing new Latin names derived from the Greek, instead of the French terms: thus he denominates the ' parenchymateux' 'sterelmintha,' from elmins, a worm, and stereos, solid; and the cavitaires' cœlelmintha,' from elmins, and coelos, hollow.' Zeder laid the first foundation of a good classification of these animals, dividing them into five classes, afterwards called families, at Rudolphi's suggestion; and these were again subdivided into genera and species. Rudolphi himself doubted the possibility of ever reducing all the species of entozoa to absolutely natural and well-defined families,

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