306 MR. BELL, HOR^ CARCINOLOGIC^ ; 



External foot-jaws, sternum and abdomen covered with distinct large and elevated 

 granulations. Abdomen in the male elongate triangular ; the &xst and second segments 

 transversely linear, the third, fourth and fifth united, with a minute tooth at the poste- 

 rior angles, two rounded elevations on the hinder portion, and a slight mesial carina ; the 

 sixth segment oblong quackate, the posterior margin armed with a strong tooth projecting 

 backwards. First pair of legs very irregular, the arms tuberculated and granular ; the 

 hand nearly as broad as it is long, distinctly carinated on the outer side ; fingers nearly 

 touching each other throughout their whole length, and slightly tuberculated. 



Colour pale brown ; the hollows of the carapace grey : there are four minute red dots 

 on the abdomen. 



Length of carapace 0-7 in., breadth 0-6. 



Two specimens (males) were obtained by Mr. Cuming, at Puerto Portrero, Central 

 America, on fine sand, at thu'teen fathoms. 



Genus Oreophouus, Riippell. 



Char. Gkn.— Testa tuberosa, postice supra pedes dilatata. Fossa; antennaria obliquae. Pedipalpi externi 

 caule exteriore arcuato, apicem versus sensim angustiore. Pedes anteriores longi, robusti; octo 

 posteriores subffiquales, sub scuto dorsali reconditi. Abdomen Maris?— FffiMiNiE late ovatum, 

 segmentis a tertio ad sextum coalitis. 



This genus, established by Ruppell, constitutes the sole form of the present family 

 which can be considered as offering a distinct approach to any other in its general 

 characters. Its relation to the Calapj)ada, and particularly to the typical genus of that 

 family, has been already adverted to ; and the principal character by which it is allied to 

 that group, and by which also the genus Calappa is distinguished from its congeners, 

 namely the latero-posterior expansion of the carapace, by which the ambulatory legs are 

 capable of being concealed, obtains in all the species at present known. The species first 

 discovered, and on which the genus was founded by Dr. Eiippell, was described and 

 figured by him in his work on the Crustacea of the Red Sea. A second species was 

 obtained by Mr. Adams in the Straits of Sunda, and appears in the Natural History 

 (Crustacea) of the Voyage of the Samarang ; and a single specimen of a third, now first 

 described, the habitat of which is unknown, exists in the British Museum. 



There is a certain approach to this genus in the general aspect of LithacUa, particularly 

 in the hollows and elevations of the shell. 



Oreophouus houridus, Riippell. Testa subtriangulatfi,, regionibus branchialibus fortitfer 



et oblique carinatis ; chelis mediocribus, manu digitis longiore. 

 Oreophorus horridus, Riippell, Krab. der Roth. Meer. p. 19. t. 4. f. 5. Edw. Hist. Nat. Crust, ii. p. 131. 

 Hab. in Mari Rubro. 



The discovery of two other species since Riippell's publication has rendered a new spe- 

 cific distinctive character necessary. The strong deep carina extending obliquely across 

 each branchial region distinguishes it from both the others, and the comparatively normal 

 form of the claws from O. reticiilatiis. 



