174 ANIMALS OF THE SEASHORE 



This snail forms a curious egg case known as 

 the sand collar. The animal glues together grains 

 of sand in the form of a collar and deposits its 

 eggs in the gelatinous substance between the sand 

 grains. (Fig. 29) The operculum (or lid of the 

 shell) is horny. 



Polinices heros Say (Moon Snail) 



PLATE XVIII. Fig. 12 



Somewhat similar to the above but without 

 the callus on the umbilicus; therefore easily disting- 

 uished by the "hole". Often larger than duplicata 

 (up to 4 inches); similar habits as the above but 

 more common in deeper water (to 238 fathoms). 

 Found between Newfoundland and North Carolina, 

 especially abundant north of Long Island Sound. 

 Used as bait for cod fish. 



Polinices triseriata Say 



Exactly similar to P. heros except for its smallei 

 size and for three rows of brown spots on the shell 

 probably the young of P. Iwros. 



Natica pusila Say 



Fig. 28 K 



Shell small ('4 inch) with white callus almost 

 completely filling the umbilicus. Lives in shallow 



