SEMINELLA. 169 



C. OBESA, C. B. Ad. PL 57, figs. 7-9, 20. 



Shell ovately ventricose, longitudinally ribbed, a little crimped 

 at the sutures, with fine revolving striae, sometimes obsolete 

 except towards the base of the body-whorl ; dusky or yellowish, 

 chestnut-banded near the suture, and again on the middle or base 

 of body-whorl. Length, 5-7 mill. 



West Indies; Mouth of St. John's River, Florida. 



G. cancellata, G-askoin (fig. 8), is founded on a dead, faded 

 specimen of this species. Reeve's description of C obesa is very 

 bad, and his figure does not correspond with his description 

 nor does it represent the species. In C. decipiens, Ad. (fig. 9), 

 the ribs are early evanescent on the body-whorl, and the aper- 

 ture has a well-defined marginal varix ; it cannot be separated, 

 even as a variety. 



C. OSTREICOLA, E. A. Smith. PL 57, fig. 19. 



Minute, subfusiform, blackish brown, longitudinally ribbed, 

 ribs slightly nodulous at the upper part ; transversely grooved 

 towards the base ; spire acute, rather longer than the mouth ; 

 whorls six, sloping, scarcely convex ; nucleus smooth ; last whorl 

 somewhat swollen, contracted towards the base ; aperture oblong, 

 dark brown within ; lip with a moderate sinus above, denticulated 

 within ; canal very short ; columella with a nodulous callosity 



above. L. 4, diam. 2 mill. 



Florida (on Ostrea mrginica). 



Said to be allied to C. nigricans, but I think its closest rela- 

 tionships are with C. obexa, Ads. The figure represents a more 

 stumpy form than that species, but the description, copied above, 

 indicates no differential character. 



C. ATRATA, Gould. PL 57, figs. 10-17. 



Shell plicately ribbed, with revolving striae at base ; lip 

 scarcely denticulated within ; dark brown, nearty black, some- 

 times with two or three brown bands. Length, 5 mill. 

 Hong-Kong Harbor (Stimpson) ; Pt. Jackson, Australia 



(Brazier) ; Aracan (Hanley) ; Viti Islands 



(Garrett) ; New Caledonia (Souverbie). 



Probably C. melanida, Duel. (fig. 11), G. levania, Duclos (fig. 



13), G. atomella, Reeve, not Duclos (fig. 10), and G. pumila, 



Souverb.'(fig. 12), are synonyms. It is a common shell, of wide 



distribution. I am much inclined to include here G. ida, Duclos 



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