MOLLUSKS 



141 



The well-known "sand-eollars" are the egg capsules nf this 

 snail. When first pressed out from the side of the animal the collar 



Fig. 100; Nortlieni Sund-colhtf Snail ctawliri;,' over a sandy bottom between two of its t 

 cocoons. From life. Cape Ann, Massacliusetts. 



is composed of a glutinous material in which the eggs are imbedded 

 ill great numbers arranged in regular rows. Sand immediately 

 adheres to the collar, and it soon hardens. These collars are com- 

 mon throughout the summer. The young snails often have two or 

 three rows of dull purple spots running spirally down the shell; 

 l)ut these disappear in the adults. 



Tlie Giant Whelks, f F tilgiir carica, and Sijeotijpus canalietilat us, 

 Fig. 101). Our whelks are the largest coiled shells to be found 

 north of Cape Hatteras. They extend from the Gulf of Mexico to 

 Cape Cod, and are especiall}' abundant off the New Jersey coast 

 and in Ijong Island Sound upon gravelly or sandy bottoms at, or 

 below, low-tide level, where they plough along with the foot partially 

 buried beneath the surface of the ground. The shells of our 

 whelks grow to be fully six inches long, and are pear-shaped, with a 

 long, tapering snout, or anterior canal. The Knobbed Whelk, fFiiI- 

 gw earicaj, may at once be recognized by the circlet of knob-like 

 protuberances around the shoulder of the body-whorl of the shell. 



