GNATIIODON.— Plate L 



coloured epidermis, inflated; posterior side ob- 

 liquely biaugular, a little produced ; anterior side 

 rather short, rounded ; ventral margin equally 

 convex. 



Recluz. ? 



Hab. ? 



This species is perhaps correctly distinguished from 

 the preceding by being shorter, less produced and 

 rostrated at the posterior end, and being on the whole 

 a much more evenly inflated shell. 



Species 4. 



Gnathodon trigonus. Gna. testa trigond, compressn, 

 latere postico biangulato, declivi, ad teriniimm 

 truncato ; umhonihus hand tantum elcvatis ; latere 

 antico Irevi, declivi. 



The trigonal Gnathodon. Shell trigonal, compressed, 

 posterior side biangular, sloped, truncated at the 

 end ; umboes not much elevated ; anterior side 

 short, sloped. 



Petit. Journal de Conchyliologie. 



Hab. California. Gull' of Me.xico. 



Much more compressed and trigonal than the two 



Species 5. (Mus. Brit.) 



Gnathodon rostr.wus. Gna. testa compressd, valdc 

 inmquilaterali, subelorujatd ; latere postico producto, 

 declivi, leviter biangulato, ante angulos margine 

 convexo ; latere antico brevissimo ; umhonibus 

 depressis. 



The beaked Gnathodon. Shell compressed, very 

 inequilateral, rather elongated ; posterior side 

 produced and sloped, slightly biangular, with a 

 convex margin in front of the angles ; anterior 

 side very short ; umboes depressed. 



Petit. Journal de Conchyliologie. 



Hab. Gulf of Mexico. 



Species 6. (Mus. Sowerby.) 



Gnathodon parvus. Gna. testa parvd, trigond, vcntri- 

 cosd, piallidd ; latere postico acute angulato, ])ost 

 angulum lato, depresso, ad termimmi rostrato ; 

 latere antico brevi, declivi; iimbonihus prominentibiis, 

 postice angulatis. 



The small Gnathodon. Shell small, trigonal, ven- 

 tricose, pale ; posterior side acutely angular, 

 broad and depressed behind the angle, beaked at 

 the end ; anterior side short, sloped ; umboes 

 prominent, posteriorly angulated. 



Petit. ? 



Hab. Mexico. 



