166 New York State Museum 



Island sound and along the shores of Long Island from 

 low water to 15 fathoms. The Brittle Starfish, Amphi- 

 pholis elegans, ranges from the New Jersey coast to the 

 Arctic ocean, the northern coasts of Europe to the Eng- 

 lish channel. It inhabits a depth from low water to 60 

 fathoms in places. The Purple Sea Cucumber is found 

 on muddy bottoms and also the Heart Urchin. Most 

 Heart Urchins inhabit deep waters. 



Of the mollusks, the gastropods are less abundant than 

 the bivalves. The Mud Flat Snail (Nassa obsoleta) is a 

 small snail, but is the most abundant shell of any con- 

 siderable size from Cape Cod to the Gulf of Mexico. It 

 ranges to Nova Scotia but is rare north of Cape Cod. 

 It fairly swarms in sheltered muddy reaches about low 

 tide. Along the New Jersey flats the little pools left by 

 the tides are sometimes so crowded with these snails that 

 they have to crawl over one another. It is most abundant 

 on the mud flats of Long Island sound which it literally 

 covers over wide areas. The Mud Flat Snail often lives 

 in brackish water and frequents all the inlets between 

 Cape Cod' and Hatteras. There are other species on the 

 Florida and California coasts. This form drills holes in 

 other shells but is itself preyed upon by young hermit 

 crabs that live in the shells after devouring the animals. 

 This snail has a black shell with a shining black interior, 

 though the shell is usually covered with mud and sea- 

 weed. The spire is blunt, but in older individuals the 

 apex is apt to be broken away. Another snail, one of the 

 Littorinas (L. minuta), is a tiny form that occurs in 

 vast numbers and serves as food for fishes and aquatic 

 birds. Many of the gastropods of the mud bottoms of 

 our coasts are northern species. Among other forms, 

 especially to be looked for on muddy bottoms off open 



