198 PINAXIA, CONCHOLEPAS. 



In placing it between Monoceros and Pseudoliva and Bapana, I 

 think that I have adopted the best alternative to the course 

 above suggested. 



C. BELCHERI, Hinds. PI. 61 , fig. 309. 



Shell very light brown, sometimes with two obscure darker 

 bands ; aperture white within. Length, 3-5 inches. 



Sfin Diego to Lower California. 



Genus PINAXIA, A. Adams. 



The shell has some resemblance to Pyrula pugilina in form as 

 well as in the revolving raised lines within the aperture, but 

 differs in possessing plications upon the columella. Mr. E. A. 

 Smith has, fortunately,* received specimens with the operculum in 

 situ : this is purpuroid, and definitely settles the proper place of 

 the genus, The animal is unknown, and a description of it and 

 its dentition particularly, is desirable. The plications of the 

 columella only appear upon old specimens, and the tubercles of 

 the shoulder of the body -whorl are not always developed. 



P. CORONATA, A. Ad. PI. 61, fig.313. 



Shell 3'ellow or white, or clouded with those colors, with, 

 usually, equidistant narrow brown revolving bands; aperture 

 yellowish within. Length, *75 inch. 



Ceylon, Philippines, Polynesia. 



I agree with Mr. E. A. Smith that it is not advisable to change 

 the well-known name of this species for the prior one of versi- 

 color (Pyrula), given by Dr. Gray, the latter not having been 

 figured, nor the description identified with this shell until very 

 lately. 



Genus CONCHOLEPAS, Lam. 



The single species has the basal groove of Monoceros and 

 Pseudoliva but its margins are defined by two sulci, giving rise 

 to two horns, instead of one, on the edge of the outer lip. The 

 immense development of the last whorl gives the shell a some- 

 what limpet-like rather than a spiral appearance. In consequence 

 of this great enlargement of the aperture the operculum, which 

 is normally purpuroid in its growth, is entirely unfitted to close 



* Ann. Mag. N. Hist., 4 Ser. xv, 301, 1875. 



