FOSSIL GASTMOPODS. 



249 



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

 strung iu bracelets and armlets by savages. Cyprma nioneta, 

 the cowry (Fig. 304), is used for money, and other shells 

 are worked into various shapes for wampum or aboriginal 

 money. Fig. 305 represents an OUvella, used by the Cal- 

 ifornian Indians as money. Murcx and Purjjura afEord 

 the Tyrian dye. 



While a few Gastropods are pelagic, living upon the high 

 «eas, such as lanthina and the Nudibranch Glaucus, most 

 of the species are submarine 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 



Fie. 204. Fig. 405. 



¥10.204.— d/prcea inoneta.— After Stearns 

 Fig. i<X>.— OUvella biplicata.— 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 char- 

 acteristic moUusks. Many live on land and in fresh water. 

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

 while those found in the temperate 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 faunse, the West Indian 

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

 Cape Hatteras ; between this point 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 suharctic seas of the circumpolar 

 regions. 



