DECAPODA. 39 



uons arranged transversely at the base of the clypeus, and three 

 teeth at the anterior extremity of each lateral edge. The tarsi 

 are spiny. The 



G. porte-pinccau; Cuv. Regne Anim., IV, xii, 1; Rumph., 

 Mus. X, 2; Desmar., Consider., XV, 1, is remarkable for the 

 numerous, long and blackish hairs with which the superior 

 surfaces of the fingers are furnished. The tarsi are without 

 spines, a character exclusively peculiar to this species. It is 

 found in the East Indies(l). 

 In our fourth section or the Orbiculata(2), the shell is either 

 sub-globular, rhomboidal or ovoid, and always very solid; the 

 ocular pedicles are always short or but slightly elongated; the claws 

 of unequal size according to the sex, those of the males being largest; 

 there are never seven complete segments in the tail; the buccal 

 cavity grows gradually narrower towards its superior extremity, 

 and the third joint of the external foot-jaws always forms an elon- 

 gated triangle. The posterior feet resemble the preceding ones, 

 and neither of the latter is ever very long. In the 



Corystes, Latr., 



The shell is an ovoidal oblong, and crustaceous;the lateral antennae 

 are long, projecting and ciliated; ocular pedicles of a mean size and 

 separated; third joint of the external foot-jaws longer than the pre- 

 ceding one, with a visible emargination for the insertion of the next. 

 The tail is composed of seven segments, the two middle ones obli- 

 terated in the males. 



A species Cancer personatus, Herbst., XII, 71, 72; Leach, 

 Malac. Brit., VI, 1, is known on the coast of France. The 

 lateral edge of its shell is marked with three notches on each 

 side. 



A second was brought from the Cape of Good Hope by the 

 late Delalande. 



Leucosia, Fab. 



Form of the shell varying, but generally ovoid or almost globular, 

 and always very hard and stony; lateral antennae and eyes very small; 

 eyes approximated. The third joint of the external foot-jaws is 

 smaller than the second, and without any apparent internal sinus; 



(1) See the article Plagusie, Encyc. Method., and the Histoire des Animaux 

 sans vertebres of Delamarck, genus Grapse. 



(2 ) The Orythia: and the Dorippes, in a natural series, would, in my opinion, 

 belong to this section, and lead to the Corystes; their shell is a truncated ovoid. 



