156 Neiv York State Museum 



another species upon muddy or sandy shores of bays. 

 It is a relative of the mussel family. It extends as far 

 north as the coast of North Carolina, but is common in 

 shallow water of the sandy shores of the West Indies 

 and Florida. The valves are fan-shaped with wide 

 sharp-edged margin and sharp-pointed apex. The ani- 

 mals attach themselves by a byssus to rocks beneath the 

 sand, and their abundance and sharp edges render wading 

 in places almost impossible. Other shells to be expected 

 on a sandy beach are the cockles, of which there are a 

 number of species occurring on both the east and west 

 coasts. The Large Cockle (Cardium magnum) is one 

 of the largest and finest cockles of the east coast of the 

 United States and probably one of the finest in the world. 

 The shell is four inches long by five and a quarter inches 

 high, of almost perfect heart shape with 33 to 37 regu- 

 larly disposed, radiating ribs and regularly crenulated 

 margin. The color is yellowish brown with transverse 

 rows of chestnut color in lines or spots. This species 

 buries itself in soft semiliquid sand and is left exposed 

 and alive at very low tide. It is abundant on Florida 

 beaches. There are several other species in Florida 

 waters and on the Pacific coast. The Iceland Cockle 

 (C. islandicum) is a cold-water species that is found 

 along the New England coast. It ranges from the Arctic 

 to Cape Cod and does not occur south of the cape. The 

 shells grow up to two inches in length and have 36 to 38 

 sharp, three-sided radiating ribs with rounded furrows 

 between. The epidermis is yellowish brown and bristles 

 into a sort of a fringe at the sharp edge of the ribs. A 

 smooth form (C. mortoni) extends up to Cape Cod and 

 is abundant in Long Island sound. It also occurs in 

 Florida. At Martha's Vineyard and the north shore of 



