FOSSIL GASTIWPODS. 



369 



Various shells, such as Margimllu, TurUnella, etc., are 

 strung iu bracelets and armlets by savages. Cyprcsa moneta, 

 the cowry (Fig. 209), is used for money, and other shells 

 are worked into various shapes for wampum or aboriginal 

 money. Fig. 210 represents an Olivella, used by the Cal- 

 ifornian Indians as money. Murex and F^irpura afford 

 tlie Tyrian dye. 



While a few Gastropods are pelagic, living upon the high 

 seas, such as lanthina and the Nudibranch Glaucus, most 

 of the species are marine and live in all seas ; the hardier, 

 most widely diffused species living between tide-marks, the 

 more delicate forms in deep water, ranging from low-water 



Fis. 209.— Cyprcea moneia.—Anci Stearns 

 Fig. 210. — Olivella bipliaita. — After Stearns. 



mark to fifty or one hundred fathoms. The abyssal fauna 

 at the depth of from 500 to about 2000 fathoms has a few 

 characteristic mollusks. 



The largest, most highly colored shells live in the tropics, 

 while those found in the temf)erate zones are less beautiful, 

 and the arctic species are the smallest and dullest in color. 

 The shells of the eastern coast of North America are 

 divided into several assemblages, or fauufe, the West Indian 

 or tropical shells, in some cases, reaching as far north as 

 Cape Hatteras ; between this i:)oint and Cape Cod a north 

 temperate assemblage occurs, and north of Cape Cod the 

 molluscan fauna is essentially Arctic ; many species being 

 common to the arctic and subarctic sesis of the circumpolar 

 regions. 



