OCR Text |
Show 50 CRUSTACEA. the Cryptopocla should be placed between the Orbiculata and the Trigona. CALAPPA, Fabr. An extremely convex shell; the forceps triangular, strongly com. pressed, dentated superiorly like a crest, and perpendicularly cover• ing the anterior part of the body, during the contraction of the feet. The third joint of the external foot-jaws is terminated like a hook, and the superior extremity of the buccal cavity is contracted and divided longitudinally into two cells by a septum. n most of them, the two posterior and lateral dilatations of the shell are incised and dentated. One species, the Calappe migrane,-Cancer granulatus, L.; Calappa granulata, Fab.; Herbst., XIII, 75, 76, vulgarly styled Coq de mer and Crabe honteux, is found in the Mediterranean. The shell is reddish and marked with two deep sulci, and unequal tubercles of a carmine red. That portion of the lateral margin which precedes the posterior dilatations, is at first nearly entire, and terminates by four very short teeth, the two first being most strongly marked; those of the edges of the dilat~tions are large, and six in number, two on the posterior rnargm, and the others lateral. There are two others on the fron. t. The. forceps are also furnished with red tubercles , an d their crest IS formed by seven teeth, the superior of which are acute( 1 ). Th. e others, such as the C. vofttc-Cancer cala'Yrl'rYl a ' L .,• Lnta' zar ,ppa for~~cata, Fab.; Herbst., XII, 73, 74, have the marginal dila-ta. ti.o n. s of the shell entire. This species inhabits the sea sm· th e viclmty of Australia and the Moluccas. .lETHRA, Leach. The .lEtlu:re differ from the Calapp<E in their very flat shell, in their forceps, whtch are not raised verpendicu1arly, and which do not overshadow th.e f~r~part of their body, and in the almost square form of the tlurd JOint of the external foot-jaws. (1) In this division come the following species of Fabricius: c t b l t Herbst., XIIT, 78; I viii, 1 ?-C. Zonhos Herbst XIII 77· C . t .t u ercu a a, x1 3 C :r ' ., • ,- • ens a us, Herbst., , ;- · marmoratua, Herbst., xl, 2.-The GuaJa apara Pison and M ~hould probably be refer.red to this species, and according to ~he citation of;:~~~~ ts the Crabe des paletuvura of the colonists of Cayenne Th 0 1 ti. f L . . . e ancer ttepa cus o mn~us 1s also a Calappa. DECAPOD A. 51 Sometimes( 1) the shell is a transversal oval, and at others(2) forms short and very wide triangle laterally dilated and rounded. The :laws are but slightly elongated, and are tolerably thick; here they are longer, angular, and remind us, as does also the form of the shell, of the Parthenopes. These latter species might constitute a sepa-rate subgenus. Finally, our last anu seventh division, that of theN oTOPODA, con-sists of Brachyura, whose last four or two feet are inserted above the level of the others, or which appear to be dot·sal and look upwards. In those where they terminate by a sharp hook, they are usually employed by the animal in seizing various bodie~, sue~ as shells, Alcyonii, &c., with which it covers itself. The tail consists of seven segments in both sexes. The tail of some of them, as in other Brachyura, is folded under, and their feet terminate in a sharp hook and are not fitted for nata-tion. Here the shell is nearly square, and terminates anteriorly in an advancing and dentated point, or it is sub-ovoid or truncated before. In the HoMoLA, Leach, The eyes are supported by long pedicles closely approximated. at base and inserted under the middle of the front. The two poster1or feet ~re alone turned up. The claws are larger in the males than in the females. The shell is extremely spinous, with a dentated projection on the middle of the front. The superior foot-jaws are elongated and sa-lient. These Crustacea inhabit the Mediterranean, and were designated by Aldrovandu:; under the name of Hippocarcini; they are the Thelxiopes of Rafincsque. Some of the species attain a great size(3). DoRIPPE, Fab. The eyes widely separated and placed at the anterior and lateral angles of the shell; the four posterior feet turned up; the claws short (1) JEthra depressa, Lam., Ilist. des Anim. sans Verteb.; Cancer scruposus, L.; Cancer polynome, Herbst., liii, 4, 5; Desmar., Consid., X, 2. (2) Parthenope fornicata, Fab. (3) Homola spinifrons, Leach, Zool. Misc., lxxxviii; Cancer spinifrons, Fab: ~ee the article HolltOLE, Nouv. Diet. d'Hist. Nat. Ed. 11, and Desmar., Cons1der., XVII, 1. The Dorippe Cuvieri, Risso, belongs to this subgenus. |