XII. CLAMS, OYSTERS, AND MUSSELS 



MoLLUSCA (continued) 

 Class I. — Pelecjjpoda (hatchet-footed) 



The clams, oysters, and mussels belong to this class. The 

 bodies of all ai'e soft and inclosed in a bivalve shell. 



Clams. — Perhaps the two species of clams best known 

 because most eaten are the long clam ( Mya) and the round 

 clam (Venus). The round clam, also known as the "qua- 

 hog," "little neck clam," etc., is characteristic of the 

 warmer waters. It is conmion on sandy shores and on 

 muddy flats, just beyond the low-water mark, from Cape 

 Cod to Texas. It burrows a short distance below the sur- 

 face, but is often found plowmg at the surface with its shell 

 partly exposed. 



On the other hand, the long clam, or soft-shell clam, is an 

 inhabitant of cooler waters and extends north to the British 

 Provinces, although it overlaps and extends into the terri- 

 tory occupied by the round clam. The long clam is re- 

 markable for the length of its si]ihons. These constitute 

 the so-called "head," or "neck" arid can be extended from 

 three to four inches l^eyond tlie valves of the shell (Fig. 60). 

 When quite young, the long clam liegins a l)arrow in the 

 mud and keeps on enlarging and deepening it as it grows 

 older, until the clam may finally reach a point eight or ten 

 inches below tlie surface. Wliile lying at the bottom of this 

 burrow, the long siphons are (>x(ended up to the surface of 



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