CAMITIA. 409 



Sub-gen. ethalia, H. and A. Adams. 



Shell orbiculai', turbinately depressed ; whorls convex, smooth 

 or transversely striated, the last rounded at the periphery ; 

 umbilicus partly closed by a callous deposit ; columellar lip 

 ending anteriorly in an obtuse, dilated callus. 



Guaraense, Qtioy and Gahn. striolatum, A. Adams. 



Genus ISANDA, H. and A. Adams. 



Shell porcellanous, orbiculately conoidal, polished ; 

 aperture sub-quadrate ; inner lip straight, forming an angle 

 with the outer lip ; umbilicus open, perspective, the 

 margin crenulated. 



Ex. I. coronata, A. Adams, pi. 46, fig. 2. Operculum, 

 I. coronata, fig. 2, a, 2, b. 



In this genus the umbilicus is open and not covered by 

 a callous deposit as in Umhoniimi, and the margin is 

 crenulated ; the texture of the shell is solid and porcella- 

 nous, and not nacreous and thin as in Margarita ; the 

 species, at present known, are from Australia and the Phi- 

 lippine Islands. 



Species of Isanda. 



coronata, A. Adams. pulchella, A. Adams. 



lepida, A. Adams. sulcifera, A. Adams. 



Genus CAMITIA, Gray. 



Shell orbicular, depressed, smooth, polished, axis im- 

 perforate ; columella spirally twisted above, forming a 



VOL. I. 3 G 



