is set in motion and in a short time a hole is bored through the clam and 

 the moon shell quietly enjoys a hearty meal, sucking the juices of the 

 animal through the hole. The shells are globular, from which they 

 receive their common name, and those of the tropics are beautifully 

 marked with purple, brown, yellow, and other colors, while not a few 

 are perfectly white. The Sigaretus, a genus closely allied to Natica, 

 has a flat, whitish or brownish, ear-shaped shell; its habits are the 

 opposite of those of the moon shell. It is slow and very timid, and 

 constantly explores the neighborhood when in motion. Both the 

 Natica and the Sigaretus burrow in the sand, and their presence may 

 often be known by the rounded heap formed by the back of the shell. 



The family Strombidce contains many large and interesting shells. 

 The animal is very powerful, and is able to leap to a considerable dis- 

 tance. Mr. Arthur Adams, a cele- 

 brated English conchologist, thus 

 describes its method of leaping: 

 "Planting firmly its powerful nar- 

 row operculum against any resisting 

 surface, It insinuates it under the edge 

 of its shell, and by a vigorous effort, 

 throwing itself forwards, carrying 



Strombus gigas with animal in its natural .. i n -,i , 



position. (Tryon.; its great heavy shell with it, the ani- 



mal rolls along in a series of jumps in 



a most singular and grotesque manner." The eyes of the animal are 

 largely developed, and are placed on a stem or peduncle. The shells of 

 Strombus vary greatly in both form and color. In some, the outer lip is 

 simply turned over, while in others, it is modified by little spines or long 

 projections. The apertures are frequently colored pink, purple, or yel- 

 lowish. The large Strombus gigas is used in carving cameos, its shell 

 being made up of several layers of different colors. It is also ground to 

 powder for the manufacture of porcelain, and in the West Indies the 

 animal is used as an article of food. The Pterocera, or spider shell, is 

 related to the Strombus, as is also the pelican's foot shell, Aporrliais. 

 The spider shell receives its common name on account of the long, 

 curved spines which extend from the lip in the adult shell. 



The augur, or steeple shells, belonging to the family Terebridce, 

 have long been objects of interest not only to the naturalist, but to the 

 layman, who places them in his house as ornaments. There are about 

 two hundred species which, although confined mostly to the tropics, 

 are found in many parts of the world. The shells are very long, and 

 are composed of many tightly wound whorls, which are smooth in some 



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