MOLLUSKS 125 
The Round Clam, Quahaug, or Little-neck Clam, (Venus mer- 
cenaria, Fig. 83), is the common hard-shelled clam of the New 
York market, and the fishery in the Middle Atlantic States is worth 
$200,000 annually. The Indians 
made their purple wampum from 
its shell. 
The hard clam ranges from 
Yucatan to Nova Scotia, but is 
common only from the Carolinas 
to Cape Cod. It is most abund- 
ant in shallow bays and estu- 
aries where it lives below the 
level of low tide. 
It is often seen lying upon 
the bottom, but is able to bur- 
row to a slight depth by means of 
its strong muscular foot which 
can be protruded from the shell 
so as to sweep backwards and 
forwards over a wide area. The siphon is short and blunt, and the 

Fig. 83; LITTLE-NECK CLAM. Long 
Island Sound. 
end displaying the two openings is forked. A continuous current 
of water flows in through the lower opening, and out through the 
opening nearest the hinge of the shell. The mantle edge around 
the lip of the valves is crumpled. The shell is covered by a grayish 
or dull brownish-gray skin, and it displays quite regular and deep 
rings of growth. The siphon is light yellow, while the foot is 
white. Kellogg finds that these clams grow very rapidly, and 
may become about three and a quarter times their former volume 
in six months. These clams feed upon diatoms and minute organ- 
isms, which are drawn into the gillchamber through the in-current 
tube of the siphon. The particles serving as food are collected by 
the slime upon the gills, and driven into the mouth by the motion 
of the cilia, while undesirable material is thrown upon the surface 
of the body or the mantle and then driven to the base of the in- 
current opening of the siphon, where it may be discharged by a 
sudden closure of the valves of the shell. 
The Razor Clam, (Hnsis americana, Fig. $4). This curious 
clam resembles in shape the handle of a razor, and is found from 
