The Olive Shells. Rice Shells. Harp Shells 



brown zigzags, remote, or so close as to form areas of solid colour. 

 Length, i J to 2 J inches. 



Habitat. — West Indies. 



The Gibbous Olive (0. gibbosa. Born.) has a stout ovate 

 shell, almost a cone in outline, not unlike that of Strombus pugilis. 

 The callus on the columella, as it approaches the spire, widens 

 and thickens, forming a great swelling, which spreads over the 

 coils, and winds a white band to the apex. The surface is creamy 

 white, darkened by an intricate network of chestnut, spirally 

 banded with white below. Length, ij to 2^ inches. 



Habitat. — Ceylon, West Africa. 



The Brazilian Olive (0. Bra:(iliensis, Lam.) is a more dis- 

 tinct cone, for its spire is flat. It is like a helmet shell. The 

 callus that overlies it leaves the sharp apex protruding, and the 

 greater part of the suture open. There is a thick round patch 

 of callus at the head of the columella. The base of the shell has 

 a broad, shiny zone of fawn colour like the lining of the lip. The 

 body whorl is crossed with fine, close-set lines ranging from 

 chocolate to pale violet. Length, 2 to 2^ inches. 



Habitat. — Brazil. 



THE RICE SHELLS 

 Genus OLIVELLA, Swains. 



This genus is very small in number of species, and in size of 

 the shells. These are cylindrical, produced into tapering spires; 

 they have thin horny operculums. The molluskslive under the 

 surface on sandy beaches. A lifted pellet of sand reveals their 

 presence. They have no eyes, nor any need of them. The foot 

 spreads into two lobes which envelope the shell. Thrown into 

 the water, an Olivella uses these lobes as swimming organs, by 

 which it speeds to cover. These shells are sold by the quart for 

 use in "fancy work." 



The Little Olive (0. mutica. Say), J inch long, or less, is 

 a delicate thin spiral, tapering to both ends. Between the lower 

 suture and a basal white band the body whorl is crossed by wavy 

 lines or bands of chocolate on a pale, almost translucent ground. 

 The aperture is half of the shell's total length. 



Habitat. — North Carolina to West Indies. 



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