(i4 OLn'KLLA. 



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

 with close Aolutions are similarly absorbed internally. 



The Olivellae atfect sandy localities, burying themselves 

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

 has observed 0. T'huelchana 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 Weinkautr in considering Lamprodoma and Callmnax 

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

 left of Olivella into three groups characterized by the extent 

 and thickness of the columellar callus ; that character being 

 decidedl}^ of gradual development through the series of species. 



0. Verreauxi, Ducros. PL 14, fig. 41, 42. 



Purplish white or yellowish white, with distant, longitudinal, 



zigzag purple stripes. Length, 5-7 mill. 



West Indies 

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

 vitidula, 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 possiblj^ a 

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

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

 has priorit}^, but the identification is not certain. 



0. MUTICA, Sa}'. PI. 14, figs. 43-55. 



White, 3-ellowish, 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 

 usuall}^ 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. puyilla, 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 boi'dering the fasciole ; these 



