CALAPPA, a genus of Brachyurous Decapod Crustacea, separated by Fabrieius, and formerly embracing the genus Hepatus of Latreille, though now restricted to the following form.
Generic Character :—External and internal antennae similar to those of the Crab (Cancer) properly so called, third articulation of the pedi palpi (pieds-mttehoires extdrieurs) terminated somewhat like a pointed hook ; chelm equal, very large, compressed, with their upper edge, which is notched or created, very much elevated, and fitting exactly to the external border of the shell or carapace, so as to cover the entire region of the mouth ; the rest of the feet short and simple ; carapace short, convex, wider posteriorly than anteriorly, and forming behind a vaulted shield, under which the posterior legs are hidden when the animal is in a state of repose; eyes mounted on short pedicles, and at a short distance from each other.
The genus is well marked by the peculiarities of the shell and ehelm, with which last, as with a shield, the Calamity cover the mouth and anterior parts, at the same time contracting up their feet beneath the posterior vaults of the shell, under whose hard protection their vulnerable parts are comparatively secured from the attacks of their enemies. They are called by the French, Migraues, and also Cogs de Mer, from their created chehe, as well as Crabes Honteux, from their appearing to hide their heads and smaller limbs behind their large ehela. Their geographical distribution is wide. The
species are recorded as inhabiting the seas of the Indian Archipelago, and of Australia, the Pacific and Atlantic octane, the seas of South America, &c. The proximate form is found in the genus (Ethra of Leach. puma.] We select as an example C. granulate, an inhabitant of the Medi terranean Sea, and found, according to M. Riaso, most frequently in the fissures of rocks near Nice, where these crabs reach to the depth of 00 feet. The same zoologist says, that the females deposit their eggs in summer ; and that there is a variety whose shell is six toothed poste riorly, and whose general colour is pale rose, with whit ish feet and brown nails.
The following is Desmarest's description of C. granulate : Carapace Term marked with four longi tudinal sutures; and having on each aide before it begins to dilate seven teeth, three short and obtuse, and four more strong and pointed upon the borders of the enlarged part, with two other smaller ones entirely behind ; front bidentated ; colour, that of flesh sprinkled with spots of carmine nal; length 2S inches; breadth 3 inches, 6 lines, French.