De Blainville divides the genus into the following sections: Species whose univalve shell is oval, much shorter than the body, prolonged posteriorly into a very long caudiform abdomen, which is provided at its termination with a pair of very short appendages. Example. Brachionus urceolaris. (Müller.) ** Species whose oval, elongated bivalve shell almost entirely Genus MYTILINA of Bory de St. Vincent. *** Species whose body is entirely covered by an oval shield, Genus PROBOSCIDIA of Bory de St. Vincent. **** Species whose body, entirely covered by a nearly circular shell, is terminated behind by a pair of very long and setaceous appendages. Genus SQUAMELLA of Bory de St. Vincent. Example. Brachionus bractea, (Müller.) BRACHIO'PODA, or BRACHIOPODOUS MOLLUSCA (Zoology), Cuvier's fifth class of Mollusks, the Palliobranchians (Palliobranchiata) of De Blainville, being the first order of the latter's third class of Mollusks (Acephalophora). the physiologist and zootomist; and we select the following General Remarks' as the part of the paper most appropriate for insertion here, premising that the generative system of the Brachiopoda is cryptandrous. On comparing together,' says Mr. Owen, 'the three genera of Brachiopoda above described, we find that although Orbicula, in the muscular structure of its arms and the proportion of the shell occupied by its viscera, is intermediate to Lingula and Terebratula, yet that in the structure of its respiratory organs its simple alimentary canal, and its mode of attachment to foreign bodies, it has a greater affinity to the latter genus. The modifications that can be traced in the organization of these genera have an evident reference to the different situations which they occupy in the watery element. Lingula, living more commonly near the surface, and sometimes where it would be left exposed by the retreating tide, were it not buried in the sand of the shore, must meet with a greater variety and abundance of animal nutriment than can be found in those abysses in which Terebratula is destined to reside. Hence its powers of prehension are greater, and Cuvier suspects it may enjoy a species of locomotion from the superior length of its pedicle. The organization of its mouth and stomach indicates, however, that it is confined to food of a minute description; but its convoluted intestine shows a capacity for extracting a quantity of nutriment proportioned to its superior activity and the extent of its soft parts. A more complex and obvious respiratory apparatus was therefore indispensable, and it is not surprising that the earlier observers failed to detect a corresponding organization in genera destined to a more limited sphere of action. The respiration indeed, as well as the nutrition of animals living beneath a pressure of from sixty to ninety fathoms of sea water, are subjects of peculiar interest, and prepare the mind to contemplate with less surprise the wonderful complexity exhibited in the minutest This class, though comparatively low in the scale of crea-parts of these diminutive creatures. In the stillness pertion, is interesting to the physiologist, and of considerable vading these abysses they can only maintain existence by value to the geologist, who finds in the fossil forms no small exciting a perpetual current around them, in order to dissiportion of those natural medals which indicate the history of pate the water already loaded with their effete particles and the stratification of our globe. We have, therefore, entered bring within the reach of their prehensile organs the ani more largely into the natural history of the Brachiopoda malcula adapted for their support. The actions of Terethan their consequence as organized beings would otherwise bratula and Orbicula, from the firm attachment of their warrant in a work of this description. shells to foreign substances, are thus confined to the movements of their brachial and branchial filaments, and to a slight divarication or sliding motion of their protecting valves; and the simplicity of their digestive apparatus, the corresponding simplicity of their branchia, and the diminished proportion of their soft to their hard parts, are in harmony with such limited powers. The soft parts in both genera are, however, remarkable for the strong and unyielding manner in which they are connected together. The muscular parts are in great proportion and of singular complexity, as compared with ordinary bivalves: and the tendinous and aponeurotic parts are remarkable for the similarity of their texture and appearance to those of the highest classes. By means of all this strength they are enabled to perform the requisite motions of the valves at the depths in which they are met with. Terebratula, which is more remarkable for its habitat, has an internal skeleton superadded to its outward defence, by means of which, additional support is afforded to the shell, a stronger defence to the viscera, and a more fixed point of attachment to the brachial cirri. Cuvier, in his anatomy of Lingula anatina, in the Annales du Muséum, first made known that organization, by which the mantle, in addition to its office of secreting the shelly defence of these bivalves, is made subservient to the circulating system. Instead of the branchia of the ordinary bivalves, he found in the situation usually occupied by them two fringed and spirally disposed arms, and that the branchia presented themselves on the internal surface of both lobes of the mantle in oblique parallel lines. He further found that these lobes were traversed by vessels of considerable size, which returned the blood from the organs of respiration, and that these branchial veins terminated in two symmetrical systemic hearts. Here was a new type of circulation, and to the mollusks which presented these interesting and important modifications he gave the name at the head of our article, significative of the fringed arms which in this class took the place of the foot or organ of progression in the cockle, &c. Lamanon and Walsh had previously taken the analogous parts of Terebratula for branchia, and Pallas, who is not quoted by Cuvier, describes the arms of Terebratula with minuteness and accuracy, but considers them as branchia, and compares them to those of a fish. De Blainville, in the Dictionnaire des Sciences Naturelles,' gives an account of the organization of Terebratula. But both Cuvier and De Blainville were led into error in their attempts to trace out some parts of the organization of Terebratula; and it was reserved for Mr. Owen, in his acute, accurate, and interesting paper, 'On the Anatomy of the Brachiopoda of Cuvier, and more especially of the Genera Terebratula and Orbicula,' published in the Transactions of the Zoological Society of London,* and derived from the dissection of specimens brought to this country by Mr. Cuming and Captain James Ross, R. N., fully to investigate the subject so as to leave little or nothing to be desired upon the subject of the anatomy of Lingula and of the two genera last named. Our limits will not permit us to follow the learned author through his memoir, the whole of which, together with the beautiful illustrations that accompany it, is worthy of the most attentive perusal by • Vol, i. p. 145. The spiral disposition of the arms is common to the whole of the brachiopodous genera whose organization has hitherto been examined; and it is therefore probable that in that remarkable genus Spirifer the entire brachia were similarly disposed, and that the internal calcareous spiral appendages were their supports. If, indeed, the brachia of Terebratula psittaceu had been so obtained, this species would have presented in a fossil state an internal structure very similar to that of Spirifer. In considering the affinities of the Brachiopoda to the other orders of Mollusca, I shall compare them, in the first place, with the Lamellibranchiate bivalves, to which they present the most obvious relations in the nature and forms of their organs of defence. To these they are in some respects superior. The labial arms are more complex prehensile organs than the corresponding vascular laminae on either side the mouth of the Lamellibranch ata. The whole muscular system is more complex; and the opening as well as the closing of the shell being regulated by muscular action, indicates a higher degree of organization than where the antagonizing power results from a property of the cardinal ligament, which is independent of vitality, viz. elas ficity. With respect, however, to the respiratory organs, less distance towards the opposite margin of the valve; the the modifications which these have presented in Orbicula loop then suddenly turns towards the perforate valve, and is and Terebratula show the Brachiopods to be still more in- bent back upon itself for a greater or less extent in different ferior to the Lamellibranchiata than was to be inferred from species. When the loop is very short and narrow, as in Ter. the structure of the branchia in Lingula; and notwith- vitrea, Brug., there is but a small tendency towards a restanding the division of the systemic heart, I consider that flected portion; but where the loop is of great length and there is also an inferiority in the vascular system. Each width, as in Ter. Chilensis, Brod., Ter, dorsata, Lam., and heart, for example, in the Brachiopoda is as simple as in Ter. Sowerbii, King, the reflected portion is considerable. Ascidia, consisting of a single elongated cavity, and not The loop, besides being fixed by its origins or crura, is comcomposed of a distinct auricle and ventricle, as in the ordi- monly attached to two processes going off at right angles nary bivalves; for in these, even when, as in the genus from the sides, or formed by a bifurcation of the extremity, Arca, the ventricles are double, the auricles are also dis- of a central process, which is continued forwards to a greater tinctly two in number; and in the other genera, where the or less extent from the hinge; but it is sometimes entirely ventricle is single, it is mostly supplied by a double auricle. free, except at its origins, as, e. g., in Ter. vitrea. This reThe two hearts of the Brachiopoda, which in structure re-flected loop, forming two arches on either side the mesial semble the two auricles in the above bivalves, form therefore plane, towards which their concavities are directed, I have a complexity or superiority of organization more apparent figured as it exists in Ter. Chilensis and Ter. Sowerbii. It than real. Having been thus led to consider the circulating is represented of a similarly perfect form in Ter. dentata, by as well as respiratory systems as constructed on an inferior M. de Blainville in his 'Malacologie; and the same appaplan to that which pervades the same important systems in ratus in Ter, dorsata is very well figured by Chemnitz; by the Lamellibranchiate bivalves, I infer that the position of Sowerby, and more recently by G. Fischer de Waldheim. the Brachiopoda in the natural system is inferior to that A similar form is also figured in another species of Tereorder of Acephala. bratula by Poli. Among the relations of the Brachiopoda to the Tunicated Acephala, and more especially to the Ascidia, we may first notice an almost similar position of the extended respiratory membranes in relation to the mouth, so that the currents containing the nutrient molecules must first traverse the vascular surface of that membrane before reaching the mouth; the simple condition, also, to which the branchiæ are reduced in Orbicula and Terebratula indicates their close affinity to the Ascidia. But in consequence of the form of the respiratory membranes in the Brachiopoda, which is so opposite to that of the sacciform branchiæ of the Ascidia, the digestive system derives no assistance from that part as a receptacle for the food, and the superaddition of prehensile organs about the mouth became a necessary consequence. The Brachiopods again are stationary, like the Ascidia, and resemble the Boltenia in the pedunculated mode of their attachment to foreign bodies. With the Cirripeds their relation is one of very remote analogy; their generative, nervous, and respiratory organs being constructed on a different type, and their brachia manifesting no trace of their articulate structure. In all essential points the Brachiopoda closely correspond with the Acephalous Mollusca, and we consider them as being intermediate to the Lamellibranchiate and Tunicate orders; not however possessing, so far as they are at present known, distinctive character of sufficient importance to justify their being regarded as a distinct class of Mollusks, but forming a separate group of equal value with the Lamellibranchiata."' The following is De Blainville's arrangement, slightly modified. Shell Symmetrical. Genus TEREBRATULA (Bruguières). Animal depressed, circular or oval, more or less elongated. Shell delicate, equilateral, subtriangular, inequivalve, one of the valves larger and more rounded (bombée) than the other, prolonged backwards into a sort of heel, which is sometimes recurved into a kind of hook-like process and pierced at its extremity by a round hole, but more frequently divided into a fissure more or less large and of variable form. The opposite valve generally smaller, flatter, and sometimes operculiform. Of that complicated loop or internal support to which the arms are attached we shall presently speak at large. Hinge on the border, condyloid, placed on a straight line, and formed by the two oblique articulating surfaces of the one valve placed between the corresponding projections of " the other. A sort of tendinous ligament comes forth from the hole or fissure above described, by which the animal fixes itself to submarine bodies. The following is Mr. Owen's description of the peculiar, complex, and extremely delicate testaceous apparatus, sometimes called the carriage-spring' by collectors, attached to the internal surface of the imperforate valve: The principal part of this internal skeleton, as it may be termed, consists of a slender, flattened, calcareous loop, the extremities of which are attached to the lateral elevated ridges of the hinge; the crura of the loop diverge, but again approximate to each other as they advance for a greater or The arches of the loop are so slender, that, notwithstanding their calcareous nature, they possess a slight degree of elasticity and yield a little to pressure; but, for the same reason, they readily break if the experiment be not made with due caution. The interspace between the two folds of the calcareous loop is filled up by a strong but extensile membrane, which binds them together, and forms a protecting wall to the viscera: the space between the bifurcated process in Ter. Chilensis is also similarly occupied by a strong aponeurosis. In this species the muscular stem of each arm is attached to the outer sides of the loop and the intervening membrane. They commence at the pointed processes at the origins of the loop, advance along the lower portion, turn round upon the upper one, and are continued along it till they reach the transverse connecting bar, where they advance again forwards and terminate by making a half spiral twist in front of the mouth. It is these free extremities which form the third arm mentioned by Cuvier. These arms are ciliate on their outer side for their entire length, but the cilia are longer and much finer than the brachial fringes of Lingula; and except at the extreme ends, which have a slight incurvation, they are uniformly straight. There is thus an important difference between Lingula and those species of Terebratula which resemble Ter. Chilensis in the powers of motion with which the arms are endowed; since from their attachment to the calcareous loop they are fixed, and cannot be unfolded outwards as in Lingula. Owing to this mode of connexion, and their ciliated structure, their true nature was much more liable to be mistaken by the early observers, though it appears not to have escaped the discrimination of Linnæus, who, as Cuvier has observed, founded his character of the animal of Anomia on the organization of one of the Terebratula which he included in that genus.' The recent species are numerous and widely diffused, and the genus appears to be capable of flourishing in extremely warm and extremely cold regions, as well as in more temperate climates. Thus some of the species have been found in the Indian seas and at Java (Ter. flavescens, Lam., for example), and Ter. psittacea, brought home from the late expedition by Captain James Ross, R. N., was fished up from a depth of twenty-two fathoms near Felix Harbour, in lat, 70° N. on the E. side of Boothia. The average depth at which Terebratula has been found ranges from ten to ninety fathoms. De Blainville has thus subdivided the species: A. Summit of the larger valve pierced with a round hole, well defined. 1. Valves triangular, with a straight anterior border. Example. Terebratula digona (fossil). [Terebratula digona, 1 2. Valves rounded at their anterior border. Example. Terebratula globosa (recent). 2. Valves sub-bilobated by the depression or emargination, which is apparent at the anterior border. Example. Terebratula Caput Serpentis (recent). [Terebratula Lyra]. a, front view; b, side view. 2. The valves sub-bilobated. Example. Terebratula canalifera (fossil). [Terebratula canalifera.] 3. The valves rounded; a mesial partition (cloison) in the larger valve, placed between two in the smaller, so as to give in the cast the representation of five distinct pieces, three for one valve and two for the other. (Genus Pentastera, Sowerby.-Fossil.) D. Opening of the heel, marginal, triangular, but much larger transversely than longitudinally. Line of articulation quite straight. 1. The small valve provided in its mesial portion with a straight flattened support, bifurcated at its free extremity; a partition (cloison) in the other valve penetrating into this bifurcation. (Genus Strygocephalus, Defrance.-Fossil.) Example. Strygocephalus Burtini. [Terebratula rubra.) [Internal view of spirifer trigonalis, showing the spiral processes.] The recent species have been found at depths ranging from the surface to seventeen fathoms; and specimens have been taken in hard coarse sand from four to six inches below the surface of the sand. Lingula has been found in a fossil state in the inferior oolite of Yorkshire, in the old red sandstone formation, and in other old fossiliferous beds. Genus THECIDEA, Defrance, Thecidium, Sowerby. De Blainville thus describes the genus. Animal entirely unknown, but very probably differing but little from that of Orbicula. Shell equilateral, regular, very inequivalve, and sufficiently similar to the Terebratula of the latter sections; one valve hollowed, the heel or hook recurved, entire, without a fissure and adhering; the other flat, operculiform, and without any trace of the internal support. Hinge longitudinal; articulation by two distant condyles, as in the Terebratula, with a large mesial tooth in the flat valve fitting between the condyloid teeth of the concave valve. Example. Thecidium radiatum. The fossil Terebratulæ (properly so called) are extremely numerous, and assist in the identification of strata from the supracretaceous group to some of the lowest formations in the grauwacke series, both inclusive. As neither Pentastera, Strygocephalus, Spirifer, Magas, nor Producta have living representatives, they are placed here from the structure of their shells, which, judging from analogy, would indicate a brachiopodous construction allied to Terebratula. Indeed De Blainville retains that name throughout but we think the differences of conformation warrant the separation of the fossils above distinguished, as subgenera of the Terebratulina. They occur principally in the more ancient fossiliferous beds. The recent species above mentioned is an inhabitant or the Mediterranean, and found among the common red coral of the Tuscan Seas. The fossil species are tolerably numerous, and Sowerby says that those which he had seen appeared to belong to the chalk, and were brought from Maastricht, and from Orglandes in Normandy. Genus STROPнOMENA, Rafinesque; (fossil.) Shell regular, equilateral, subequivalve; one valve flat, the other slightly excavated: articulation straight, transverse, with a small projection notched or dentelated transversely. No trace of an internal support. Example. Strophomena rugosa. [Strophomena rugosa.] View of lower side. As Strophomena has no living representatives, at least none yet discovered, there can be no description of the animal, which is however, judging from the construction of the shell, most probably brachiopodous. The fossil genera Plagiostoma, Dianchora, and Podopsis (see these titles) are placed by De Blainville under this section. We do not however think that there is such pregnant evidence of a true and entire brachiopodous organization, as to warrant this decided position under the Brachiopods. Indeed De Blainville himself says that some of the Plagiostomata are of the family Terebratule, and that the others (he instances Plagiostoma Mantellii) are entirely different, and he allows that these last ought to form a distinct genus of the family of Subostraceans. Defrance places Podopsis among the oysters. Shell unsymmetrical, irregular, always adherent. Genus ORBICULA, Lamarck. Shell orbicular, very much compressed; inequilateral, very inequivalve; the lower valve very delicate, adhering; the upper valve patelliform, with the summit more or less inclined towards the posterior side. Fissure of adhesion in the lower valve subcentral. Hinge toothless. Example. Orbicula lamellosa. VOL. V.-2 S F [Orbicula lamellosa. A single specimen, showing the cilia. The recent species are found attached to stones, shells, sunken wrecks, &c., and have been found at depths ranging from not far below the surface to seventeen fathoms. Fossil species are said to have been found in the lower green sand of Sussex, in the Speeton clay of Yorkshire, in both the great and the inferior oolite, in the carboniferous limestone, and in the Ladlow rock below the old red sandstone.* G. B. Sowerby has satisfactorily proved that Lamarck's genus Discina must be expunged, it having been formed from specimens of Orbicula Norvegica, sent by Sowerby to Lamarck. Genus CRANIA, Retzius and authors. G. B. Sowerby, who has done so much in the thirteenth volume of the Linnean Transactions' to unravel the confusion which had previously been created by authors, gives the following generic characters. Shell inequivalve, generally equilateral, rather irregular, orbicularly subquadrate, and flattish; the upper valve patelliform, having its umbo or vertex rather behind the centre; the lower valve attached by its outside, the greater part of it being generally extended over the substance to which it adheres; (and in this respect it differs greatly from Orbicula, which is attached by means of a ligament which passes through a fissure in the centre of the lower valve.) There are four muscular impressions in each valve; of those in the upper valve two are in the posterior margin and the other two nearer the centre, but not always very near to each other; of those in the lower valve, two are nearly marginal and rather distant, but the other two are nearly central, and so close together, that they appear to form but one: they in general have a small projection between them; and the whole of the muscular impressions in the lower valve are frequently lost by decomposition in the fossil species, so as to appear only three oblique per forations, as Lamarck has described them. Example. Crania personata. The recent species, and this is the only one known, is found adhering to stones and shells at very great depths. It is stated in the Zoological Journal,' by the Rev. M. J. Berkeley, that a specimen of Crania personata was taken by Captain Vidal, at the depth of 255 fathoms. There are several fossil species, mostly from the chalk. BRACHY CERUS, a genus of coleopterous insects of; the family Curculionidae (included in the genus Curculio by Linnæus). Generic characters-rostrum short; antennæ inserted towards the apex of the rostrum, short, nine-jointed; the basal joint longest, the terminal joint forming a knob; tarsi with all the joints entire, and without pubescence be neath. The species of this genus are apterous, and generally very rough. They appear to be peculiar to the south of Europe and Africa, and live upon the ground. BRACHYPODINE (Zoology.) Swainson's name for a sub-family of the Merulidae, containing the following genera or rather sub-genera : Brachypus, Swainson, thus characterized by him: bill short; rictus (gape) bristled. Feet small, weak: lateral toes equal. Hinder toe as long as the tarsus. Type Brachypus dispar, Sw. (Turdus dispar, Horsfield.) Chloropsis, Jardine and Selby. Bill more lengthened; the tip much hooked; the notch forming a small distinct * Broderip, Trans. Zool, Soc, vol. i, p. 141. tooth. Rictus smooth. Feet small; lateral toes unequal; the hinder toe rather shorter than the tarsus. Töra, Horsfield. Bill nearly as long as the head; lengthened conic. Rictus smooth. Tarsi somewhat lengthened; the anterior scales divided. Tail even. Type Iöra scapularis, Horsfield. Andropadus, Swainson. Bill short; the upper mandible serrated near the tip. Neck with setaceous hairs. Type L'Importan, Le Vaillant. Hæmatornis, Swainson. Bill short; rictus bristled. Lateral toes unequal. Hinder toe shorter than the tarsus. Types. 1. Chrysorrhoëus, Le Vaillant. 2. Turdus hæ marrhous, of authors. 3. Turdus bimaculatus of Horsfield. 4. Erythrotis of Swainson (Lanius jocosus of Linnæus). Mr. Swainson does not seem to have been aware that the appellation Brachypus had previously been conferred by Fitzinger on a sub-genus of Saurians, belonging to the Chalcides of Daudin, and it should, therefore, be no longer used to distinguish a sub-genus of birds. The term at the head of this article, which Mr. Swainson has applied to the sub-family, might be changed with advantage; for it may be liable to create confusion when unexplained by contexts, and leave the reader in doubt whether a sub-family of birds or reptiles is intended. For Mr. Swainson's further account of Brachypodinæ, see Fauna Boreali-Americana, vol. ii., where the characters of the subgenera given above will be found. BRACHY PTERYX (Zoology), a genus of birds approaching to Saxicola, thus defined by Dr. Horsfield: Essential character. Bill with the culmen carinated between the nostrils, the sides being flattened, and rounded towards the apex with the sides convex; edges subinflected. Wings very short and obtuse. Tail moderate and rounded. Feet elongated and weak; the tarsi slender; the toes very slender and the claws very much compressed. Hallux or hind toe comparatively large. Natural character. Bill moderate, rather strong, subcultrated, broader at the base than it is high, subconical beyond the middle, attenuated; the culmen, or ridge, carinated and angulated between the nostrils, with the sides flattened, and beyond that point somewhat thickened, rounded, the sides being convex, arcuated towards the apex and notched. Mandible depressed at the base, the sides erect, turned inwards towards the apex, myra rather strong, subinclined. Edges of the jaw and mandible subinflected. elongated, obtuse hollow, covered above and posteriorly by Nostrils very large, placed in a somewhat rounded, basal, a membrane. Wings very short and obtuse. Quills entire, the first subspurious, from the second to the fifth gradually increasing, from the fifth to the tenth longer and nearly equal, the rest gradually shortening. Tail moderate, rounded; the feathers twelve. Feet elongated and weak. Tarsi slender, twice as long as the middle toe. Toes compressed, very slender, the middle longest, the lateral toes nearly equal, the outer toe sub-coalescing with the middle toe at the base. Claws very much compressed and very acute. the genus is founded is thus described by the author :Brachypteryx montana, Horsfield, the species on which Weight of the male five, and of the female six, drachms. In the length of the two sexes scarcely any difference is perceptible. The measure is nine inches and nine lines from the tip of the bill to the end of the tail; to the extremity of the claws the length is six inches. In the male, the head, neck, and breast have a dark indigo blue tint, inclining to black, with a greyish reflection on the surface, variegated with lighter and darker shades; on the throat and the lower part of the neck this colour passes into grey; on the forehead it is more intense, inclining to black. Above the eyes is an oblong white spot. The back, the wings above the shoulders, the coverts of the tail, the vent, hypochondria and thighs are deep chestnut brown, with a ferruginous reflection. The wings underneath, and the tail at the extremity and underneath, are pure blackish brown; the shafts of the quill and tail feathers are black and shining. The inner vanes of the quills and the tail feathers generally have a very deep brown colour. The exterior vanes of the tail feathers are slightly tinted with the ferruginous lustre of the upper parts. The lower parts of the breast and abdomen are whitish. The plumes on the posterior portion of the body are very thickly disposed; the vanes consist of long delicate, silky, pendulous laminæ or filaments, forming a |