126 SEA-SHORE LIFE 
Labrador to the Florida Keys. The shell becomes about six inches 
long and is only one inch wide. The clam has a long muscular foot 
which can be withdrawn within the shell but may be protruded 
fully five inches out from the anterior end. By means of this foot 
the clam burrows through sandy beaches with wonderful rapidity, 

Fig. 84; RAZOR CLAM, Annisquam, Mass, 
so that it is practically impossible to capture one of them with a 
spade after it has once buried itself beneath the surface. At low 
tide the clam often comes to the surface and remains with the pos- 
terior end of its shell projecting, allowing the short siphon to pre- 
trude into the air. If it be disturbed it darts rapidly back into its 
burrow. This clam is very palatable, but the difficulty of capturing 
it prevents its being sold in any quantity in the markets. It is 
found commonly within sandy sea beaches or sand bars where the 
water is not brackish. 
The Sand-Bar Clam, (Siliqua costata, Fig. 89). This shell is 
about one and three-quarter inches long and three-quarters of an 
inch wide. It lives within 
loose sandy beaches and 
bars, in shallow water, but 
does not extend above low 
tide level. It occurs from 
Nova Scotia to the Caroli- 
nas but is found only in 

situations where the ocean 
water is pure. The shell 
is covered with a rich brown skin, which gives it a polished sur- 
Fig. 85; SAND-BAR CLAM. Cape Ann, Mass. 
face. The siphon is slender but quite long, while the foot is broad 
