378 MARINE INVERTEBRATES 



learned its value long ago, and hold specimens of it at very sub- 

 stantial prices. It is worn as an ornament by chiefs and as a mark 

 of distinction. The well-known C. moneta, also a native of the 

 Pacific Islands, has been very extensively used as money through- 

 out the South Seas and in Africa. There are many collectors of 

 shells who confine their efforts almost exclusively to this and to 

 one or two of the other " aristocratic " genera. From an esthetic 

 point of view this is very natural, but biologically the less 

 pretentious mollusks are quite as interesting. 



Of the one hundred and fifty or more species in existence only 

 three are to be found upon the Atlantic coast of the United States, 

 and the chances are decidedly against the finding of any of them 

 north of extreme southern Florida. 



C. exanthema. A species not uncommon at Key West, where it may 

 be seen slowly crawling 1 about the mangrove roots near the water's 

 edge. It attains a length of from four to six inches, and is so highly pol- 

 ished that a good specimen could be used as a mirror. In color it is 

 shining, light chestnut, clouded with purple ; the lips are a dark, very rich 

 chestnut ; over all are whitish spots which appear to shine forth from 

 beneath the enamel. Lengthwise along the middle of the back is a 

 zone of lighter color which reflects a purplish sheen. (Plate LXX.) 



C. spurca. Another Floridian species, properly belonging to the 

 West Indian fauna. It is not more than one half an inch long, and is 

 white in color, but it is so thickly dotted with yellow spots upon the bacjc 

 that it would pass for a yellow shell. The base is pure white. . The sur- 

 face of the shell glistens in the light. 



GENUS Trivia 



In the genus Trivia the shell is shaped in every way like that of 

 Cyprcea, but its surface is never smooth. In the middle of the 

 back is a longitudinal groove, from which run transverse 

 ribs, which continue around to and enter into the aperture. The 

 shells are always small, never exceeding one half of an inch in 

 length, and their color is generally reddish or brownish, passing 

 to pink. 



T. pediculus. A Floridian species, first described by the great natu- 

 ralist Linnaeus. Like most of the descriptions of the earlier naturalists, 

 this is very short and inadequate, and would apply equally well to al- 

 most any Trivia. The color is rose-pink, with several large brownish 

 splashes on the back. The spire is entirely hidden. It is found in shal- 

 low water in pools, and on the beach, after storms. ^Plate LXX,) 



