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Show 44 CHUSTACEA. portions of the claws, and the numbet· of their caudal segments, ate removed from them, as well as ft·om the other anterior subgenera, by the insertion of their lateral antennre under the snout, and their approximation to the fossulre lodging the intermediate ones, being closet· than to those which receive the ocular pedicles(l). In the two following subgenera the ocular pedicles are short or moderate, as well as in the preceding ones. But the claws, even those of the males, are hardly thicker than the following feet. The tail always consists of seven segments. In the MAIA, Leach, The second joint of the lateral antennre .seems to arise from the internal canthus of the ocular fossre. The hand and the joint which precedes it are nearly of the same length. The shell is ovoid. This subgenus established by Lamarck, and originally consisting of a great number of species, comprises, at present, according to the method of Dr Leach, but one, the Cancer squinado, Herbst, XIV, 884, 5, lvi; lnachus comutus, Fab. It is very common on the coast of France and in the Mediterranean, where it is called .!lraignee de mer. It is one of the largest of the European Crustacea, and the Maia of the ancient Greeks, figured on some of their coins. They attributed great wisdom to it, and considered it as sensible to the charms of music. MIOIPPE, Leach. . 1'he first ~oi~t of the lateral antennre curved, dilated at its supe· nor extremity ~nto ~ ~ran~verse and oblique blade, closing the ocular fossre; t~1e ensumg JOint mserted under its superior margin. The shell, viewed from above, appears widely truncated before· its an· terior extremity is inclined, and terminates in a sort of cl;peus or dentated rostrum(2). The STENOOIONOPs, Leach, Is distinguished from all the other subgenera of this tribe by (1) Maia taurm, Lam.; Cancerwrnudo, Herbst., lix, 6. . N.B. The gen~s .O.mathia of M.P. Roux, Hist. des Crust. de Ia Mediterr., &c., ltv. I, does not.ddfer fro~ my Pericera-it even appears to me to have the same ty_re. The Lithograpluc plates which accompany this work are distinct! and fa1tbfully executed. y (2) Cancer C?·istattts, L.; Rumph., Mus. Vll£ H b , , 1, the male.-Cancer phylira, er st .• lviii, 4; Desmar. Consider., XX, 2. DECAPODA. 45 long and slender ocular pedicles which protrude from their fossulre( 1 ). There, the under surface of the feet presents neither ranges of den-tations nor claviform cilia. Those of the first pairs, at least, are one half longer than the shell, and frequently much longer. The body is usually more abbreviated than in the preceding subgenera, being either nearly globular, or formed like a shortened egg. A species of this tribe,-Maia retuja, Coli. du Jard. du Roi, whose shell is woolly and forms a truncated ovoid1 or is obtuse anteriorly; whose strongly curved elongated ocular pedicles are received into fossulre situated under the lateral margin of the shell ; whose carpus is elongated, as in Maia, presents another character which exclusively distinguishes it, viz. the length of the feet seems to augment progressively from the second pair onwards, or at least to differ but little. It is the type of the genus CAMPOSOI.A, Leach. In the others, as usual, the length of the feet progressively di· roinishes from the second pair to the last. In some of them, the ocular pedicles, although much shorter than in the Stenocionops, are always salient, and the third joint of the pedicle of their lateral antennre is as long, or even larger, than the preceding one, the antennre themselves terminating in a long setaceous stem. They approach the Micippes; such is the HALIMus, Latr.(2) In those which constitute the two following sub-genera, the ocular pedicles are susceptible of being entirely retracted within their fossulre, and are protected posteriorly by a dentiform projection, or angle, of the lateral edges of the sh.ell. The second joint of the peduncle of the lateral antennre is much larger than the following one; they are terminated by a very short stem resembling an elon-gated stylet. HvAs, Leach. Lateral edges of the shell dilated behind the ocular cavities which are large and oval; external side of the second joint of the lateral (1) CancBr cervicornis, Herbst., lviii, 2, from the Isle of France. M. Desmarest was mistaken in citing, as the type, Consid. Gen. sur les Crust., p. 153, the Maia tau1-us, Lamrirck. (2) Two species, one of which appears to be allied to the Cance?' sttperciliosus, L., Herbst, XIV, 89. |