240 FISHEEIES OF THE UNITED STATES. [56] 



Siliqua patula, Dixon. 



This species, the "Flat Razor Clam", is found from Alaska to Cali- 

 fornia, and is especially abundant along the northern coast. It grows 

 to a length of four or five inches, and is covered with a glossy, rich 

 brown epidermis. It does not burrow very deep, and is esteemed de- 

 licious food, but is not extensively used. 



Platyodon cancellatus, Conrad. 



This is the "Date Fish", a species closely resembling Mya arenaria, 

 found along the coast of California from San Francisco southward. 

 It exists in great abundance in Baulinas Bay and at Santa Barbara. Its 

 habits are essentially those of the " soft clam", and it forms one of the 

 staple food shell-fish of the Pacific coast. 



Zirphcea crispata, Morch. 



This mollusk, though widely distributed along the Atlantic coast of 

 the United States, is not of commercial importance, while on the Pacific 

 coast, where it is known as the "Date Fish," it is found in the markets 

 and eaten by numbers of people. The Pacific variety is, however, con- 

 siderably larger than that ordinarily found on the eastern coast. It 

 is a northern species, not occurring south of Eastern Connecticut, and 

 extending to the Gulf of St. Lawrence, in the Atlantic, and on the west 

 coast being rarely found south of San Francisco. It is fossil in the 

 Post-Pliocene of Maine. All the Pholadidce are borers, and Z. crispata is 

 no exception, but it is not very destructive, usually preferring mud and 



clay to wood. 



Macoma nasuta, Conrad. 



This species, called the " Tellen", is very common on the Pacific coast, 

 and has a wide range, extending from Kainschatka to Mexico, but is 

 rare south of San Diego. It is abundant in San Francisco Bay, and it 

 was evidently eaten largely by the aborigines, as the shell-mounds in 

 the vicinity of the bay are largely composed of shells of this species. 

 It inhabits muddy flats, burrowing quite deeply, and reaches the water 

 by its two small, red siphons. The usual length is two inches. It is 

 eaten on the Pacific coast by all classes. 



Tapes slaminea, Conrad. 



This species, known as the "Carpet-Shell", " Little-Neck Clam," and 

 "Hard- Shelled Clam", is abundant on the whole Californiau coast, and 

 is found in all the markets. Tomales Bay furnishes a large number, ns 

 do other points where the animal is to some extent protected, as at 

 Baulinas. It is usually found between tide-marks, buried one or two 

 feet in the bottom, which may be either muddy or stony. This and 

 other species designated as " Little-Neck Clams " occupy a similar place 



