OYSTERS, CLAMS, AND OTHER MOLLUSKS 243 



hard clam is the only one of commercial importance. 

 Some surf-clams, "skimmers," are marketed in New 

 York. A long, narrow clam called the razor is the 

 principal species taken in Washington. Mya, the soft 

 clam, is known by many local names ; the more com- 

 mon are long clam, long neck, squirt-clam, maninose, 

 sand-gaper, and old maid. Venus, the hard clam, is 

 commonly called quahog or quahaug, round clam, 

 and, in the smaller sizes, cherry-stone and little-neck 

 clam. 



Larval clams resemble young oysters in that they 

 pass through a free-swimming stage. These minute 

 clams rotate spirally as they move through the 

 water. When the little clam is only one three-hun- 

 dredth of an inch in diameter, it grows little shells. 

 Millions of the free-swimming clams can be found 

 over the clam flats during the summer months. After 

 swimming for a few days, the young clams settle to 

 the bottom and attach themselves to shells, seaweeds, 

 or pebbles by means of minute threads which they 

 spin. At this stage, the young clams do not remain 

 stationary but often detach their anchors by means 

 of their feet. When the young clam has become about 

 a hundredth of an inch in length, it burrows into the 

 bottom. Newly buried, soft clams occasionally come 

 to the surface, creep a short distance, and then bur- 

 row in again. Once the clams have reached a half- 

 inch in length, they burrow in deeper and never rise 

 to the surface again. Soft clams grow from a length 

 of one inch to three inches in a single year, but the 

 growth of the hard clams is much slower. 



The culture of both the hard and the soft clam 



