OTHER BIVALVE MOLLUSKS 89 



mon length of the shell is two or three inches. I once 

 gathered quite a quantity of them in San Pedro har- 

 bor. It is said that the wild ducks are particularly 

 fond of this species, and in one instance, at least, 

 the quacking of a flock of ducks revealed to a shell 

 hunter the place to dig for the shells. The variety 

 subteres^ Conr., is small, compact, with violet rays 

 and a very dark epidermis. It occurs with the com- 

 iTion form. 



Sangubiolaria niittalUi^ Conr., Nuttall's Sanguino- 

 laria, is a southern species, having a thin, oval shell, 

 partly covered with a dark brown epidermis. The 

 colors of the shell are white and lilac, the latter being 

 sometimes beautifully rayed. One valve is much 

 more bulging than the other, and the external liga- 

 ment, just behind the beaks, is very prominent. The 

 shell is two or three inches long. 



We now come to the Tel lens, whose name is de- 

 rived from a Greek word meaning a certain kind ot 

 mussel ; but when we use the term we think of a flat, 

 thin bivalve shell with very small hinge-teeth and a 

 deep pallial sinus. Many of the tropical Tellens 

 are bright and beautiful, while those that live in our 

 cooler waters are far less ornate. The first species 

 that we will consider is named l^ellina hodegensis^ 

 Hinds, the Bode- 

 ga Tellen. Fig- 

 ure 6^ shows the 

 inside a}:)pearance 

 of a right valve. 

 Externally the 

 shell is creamy Fig. 65 



