512 



MOLLUSCA. 



TIIK STROMBID^. 



The animals of this lainily. called M'inr/ Shells, have the outer lip of their sliell much ex- 

 panded ; the f<^ot is narrow and ill-adapted for creeping : 

 the proboscis is large and thick, and the eyes large, sup- 

 ported on long, stout footstalks, from the sides of Avhich the 

 short tentacles rise. The species feed principally on car- 

 rion, and for molluscous animals they are very active. They 

 progress by a sort of leaping movement, turning their heavy 

 shell from side to side. 



The Stromb, Strombiis ^?2//7?7/s, is found in the West In- 

 dies, the Red Sea, India, Mauritius, and various other seas. 

 The Fountain Shell, S. gigas, found in the West Indies, 

 is one of the largest of living shell-fish, sometimes -vveighing 

 four or five pounds. As it becomes old, the apex and spires 

 are filled with solid shell. Immense quantities are annually 

 exported from the Bahamas for the manufacture of cameos 

 and for porcelain works. In 1850, three hundred thou- 

 sand were brought to Liverpool alone. 



The Conch Shells, formerly much used in this country 

 by farmers to call their workmen to their meals, are of this 

 genus. 



The Scorpion Shell, Pteroceras lamhis — found in India 

 and China — is of this family. Ten living and a hundred fossil species are known. 



THE TTJRRITELLID^. 



In these, which may be called Tower Shells, and which derive their name from the Latin, 

 tiirris, a tower, the shell exhibits a great variety of form, sometimes being semi-globular and 



sometimes elongated, and 

 tapering gradually to the 

 apex. The Turrifella 

 rosea has the shell elon- 

 gate, conical, smooth, 

 and of a rosy color : 

 found in New Zealand. 

 The T. terebra, is found 

 There are fifty living and one hundred and seventy fossil species 



THE STEOMB. 



THE TUBBITELLA TEREBBA. 



in the African and Indian seas, 

 of this family. 



THE LITTORINID^. 



This includes the Common Periwinkle, Littorina littorea, found on the sea-shore in all parts 



of the world. It is oviparous, and inhabits the 

 lowest zones of sea-weed between tide-marks. 

 The L. rudis frequents a higher region, where 

 it is scarcely reached by the tide. The peri- 

 ■winkles are exceedingly small, but their tongue 

 is two inches long. Immense numbers of them 

 are devoured by birds of various kinds. Nearly 

 allied to the periwinkle, are the Stair-Case 

 Shell, of the genus Solarium, the Carrier 

 Shell, of the genus Phorus, and the Looping 

 Snail, of the genus Truncatella. 



To this tribe belongs the genus Scalaria, pop- 

 ularly called Wentle- Traps; the shell is mostly white and lustrous, turreted and many-whorled ; 



THE WENTLE-TRAP. 



