400 MARINE INVERTEBRATES 



FAMILY OLIVIDJE 

 GENUS Oliva 



The genus Oliva is one of the favorites among collectors. It 

 comprises smooth, highly polished, porcelanous, and oval shells 

 with a deeply notched, long, narrow aperture. The columellar lip is 

 usually heavily calloused and ornamented with oblique folds. The 

 animal's foot is very large, and extends laterally into lobes which 

 curve back over the shell. In front the propodium is very large, 

 forming, as in Natica and Polynices, a sort of plow. The mantle 

 lobes almost cover the shell when extended. 



O. literata. The only American example out of some sixty known 

 species. It is found in great abundance in sandy tide-pools along the west 

 Florida shores. It ranges from Ilatteras to the West Indies, and 

 may be looked for in stations similar to those of the naticas. It is ex- 

 ceedingly active, crawling rapidly over the sand or burying itself very 

 quickly out of sight, and is carnivorous. The shell is highly polished, 

 about two inches long, and pale yellowish-white in color, covered with 

 longitudinal, angulated, or zigzag lines of chestnut. The spire is short, 

 the sutures channeled, and the columella calloused with white enamel, 

 and obliquely striated. (Plate LXXVII.) 



GENUS Olivella 



The genus Olivella resembles Oliva very closely in conchologi- 

 cal characters, but the shells are, with few exceptions, exceed- 

 ingly small, and usually have a somewhat more elongated spire 

 than is the case in the genus Oliva proper. The animal of Oli- 

 vella seems to be a degenerate, for it possesses neither tentacles 

 nor eyes. In habit and station it resembles Oliva. 



O. mufica. In Floridian waters this species is exceedingly common. 

 It is not more than one fifth of an inch long, is highly polished and shin- 

 ing, and yellowish -white in color, with revolving pale rufous bands. It 

 has the typical oliva-shape. 



O. biplicata. A Californian species of considerable interest, the 

 largest of the olivellas. It was evidently used by the aborigines as 

 wampum or as ornaments, for a great many specimens are found among 

 buried Indian relics. This species is about the size and. shape of an 

 olive. The spire is short, though longer than the typical Oliva spire, the 

 shell is smooth and highly polished, and the columella is thickly cal- 

 loused, and has two entering folds near the base. The color is creamy- 

 to dove-color, with a purple sheen over all, ?nd purple markings 



