l')4 OI.IVKLLA. 



and I presume that it will prove to be the fact that all shells 

 with close volutions are similarly absorbed internally. 



The Olivelhxj affect sandy localities, burying themselves 

 beneath the surface, upon which they leave no trace. D'Orbigny 

 has observed 0. Trhuelcharia suddenly expand the lobes of its 

 foot, and using them to beat the water like the wings of the 

 pteropods, shoot rapidly through the element. 



I follow Weinkauff in considering Lamprodoma and CalHanax 

 subgenera of Oliva, but I cannot follow him in dividing what is 

 left of OlivrUa into three groups characterized by the extent 

 :ind thickness of the columellar callus ; that character being 

 decidedly of gradual development through the series of species. 



O. VERREAUXT, Ducros. PI. 14, fig. 41, 42. 



Purplish white or yellowish white, with distant, longitudinal, 



zigzag purple stripes. Length, 5-7 mill. 



Wi'*t Indie* 

 The spire is more produced than in the usual form of 0. 



nitidula, the stripes are larger and more distant, there are no 

 traces of bands and it has not the fasciculated markings at the 

 suture and base so common in nitidula ; still, it is possibly a 

 variety of that protean species. It is the 0. mutica of Reeve, in 

 part, and probably 0. mica, Duclos (fig. 42) ; the latter name 

 has priority, but the identification is not certain. 



O. MUTICA, Say. PI. 14, figs. 43-55. 



White, yellowish, bluish ash or deep chocolate, when very 

 dark, the color results from the coalescence of three bands of 

 chocolate-brown, which appear upon the lighter colored, typical 

 specimens ; these bands vary in width, the centre one being 

 usually. the broadest; sometimes they are all so broad as to 

 appear to be the ground-color, the narrow interspaces forming 

 two white bands. The spire is produced. Length, 10-16 mill. 



North Carolina to West Indies. 



With the typical form I unite 0. pusilla, Marrat (figs. 45, 46), 

 and 0. rufifasciata, Reeve (fig. 47). 



Var. NITIDULA, Dillwyn. Figs. 48-55. 



Spire shorter, shell comparatively wider, bands very faint or 

 obsolete; yellowish or pink-brown with a chocolate or chestnut 

 band at the suture and another bordering the fasciole ; these 



