CARINA'RIA, the name of a genus of Mollusc; arranged by Cuvier under his fifth order of Gasteropods (Lamarck's Heteropoda) as the type of that order, and by De Blainville under the first family (Nectopoda) of his order Nucleobran,chiata. The shells of this genus were formerly known to collector') under the names of Venus's Slipper and the Glass Nautilus : indeed one of the species is the Argonav,ta vitreus of Gmelin. • The body of the animal is sub-cylindrical, elongated, transparent, dotted with elevated points, prolonged posteriorly, and furnished towards the upper part of its posterior extremity with a sort of fin, which performs the part of a rudder. A reddish thin compressed sub-circular fin, beautifully reticulated by decussating muscular fibres, furnished with a sort of acetabulum or sucker, rises from the belly nearly opposite to the point on the back occupied by the shell. With the aid of this fin it floats along. M. Verany says that, notwithstanding the greatest possible attention, he has not been able to discover the use of the sucker, or rather auctorial disc, in the ventral fin; but there can be little doubt that it is analogous to the foot in Gasteropods, and that the animal avails itself of its powers of adhesion by sticking to rocks or other submarine bodies, and thus lying at anchor, as it were, in repose, with the frail shell that protects the circulating and respiratory organs, together with the liver and generative gland, lowermost—the same position occupied by it when the animal is in motion.
The head is capable of contraction within the body, and is provided with a sort of retractile proboscis. There are two tentacula of some length and of a subconical shape, placed laterally at the insertion of the head ; and there are two eyes situated at the base of the tentacula. The mouth is furnished with a circular jaw, armed with four rows of teeth, of which the two internal ones are fixed and small.
The organs of respiration, together with the heart and vent, are protected by a delicate transparent shell, somewhat compressed, without a spire, but with a summit a little recurved backwards, and the opening wide, entire, and oval. The vent is under the edge of the mantle, which envelopes the organs above mentioned and lines the shell.
The sexes, according to M. Verany, are separated as in the Firolm (Pterotrachea) ; the sexual organ of the male being placed a little anteriorly on the right side under the subcircular belly-fin ; that of the female is near the vent.
The digestive organs consist of a retractile tube furnished within with a horny rasp, and a short cesophagus, opening into a slightly dilated stomach, which is continued into an intestinal tube passing straight towards the shell, into which it enters, and making a convolu tion terminates in the vent.
There is between the eyes a ganglion from which many nerves are given off, and of these six are directed forwards and four backwards.
Of the six directed forwards two go towards the mouth, and appear to provide for the action of the proboscis, two belong to the tentacula, and two to the eyes. Of the four directed backwards, two go directly to the nucleus in the shell, and the other two unite under the fin, whence they ramify into five branches, three of which are appropriated to the belly-fin, and two go towards the tail.
Carinaria Mediterranea may be taken as an example of the genus. M. Verany states that it is to be found all the year on the coasts (in the neighbourhood of Nice), but that it is sufficiently abundant in the months of May, June, and July. Ho further observes that it is rare to find it with the shell entire, that it feeds on gelatinous bodies and on very small fishes, such as A thcrina nana (the Dwarf Atheriue), and that he has often found in the stomach the remains of other Carinarim, which satisfies him that the species in mutually destructive.
Dolle Chinje, who has placed the animal in its proper position with relation to the brain, has given a careful and detailed account of its organisation in his ` Memorie guile Storia a Notomin degli Animali sense Vertebra del Regno di Napoli,' voL ii. p. 214, illustrated in his plates 14 and 15. Dello Chiaje makes the spermatic canals rise at the posterior base or insertion of the ventral fin and proceed to the genital organ, near the origin of what we have termed the rudder-fin ; but ha gives no external view of the apparatus so conspicuous in M. Verany's figure.
Curimaria has never yet been taken in any other thou warm Inti tudes. Three species, C. ritrea, C. fraydia, And C. Mantes-ranee, are recorded without reckoning Lamarck's C. rymbium.
The above is copied from the Iconographic of Cuvicr's ' Animal Kingdom,' and represents the Carinaria with its back uppermost. It is denominated Curinerie rymbium, but there can he no doubt that it is Carinaria 3Irditerranea.