100 



WEST COAST SHELLS 



may be gathered by anyone who will take the 

 trouble to dig. Figure 77 gives a view of the 

 inside of a left valve, showing the spoon-like hinge- 

 tooth, the muscle-scars, and the pallial sinus. The 

 valves are rather thin and brittle, gaping at the ends, 

 and the edges are covered with a gray epidermis. The 

 common length of grown specimens is three inches. 



Mya truncata^ Linn., the Blunt Mya resembles the 

 last, but the siphon end is truncated, as if it had been 

 chopped off. This species also lives in the northern 

 Atlantic and is reckoned as circumboreal, coming 

 down on the west side of the continent as far as 

 Puget Sound. 



Cryptomya californica, Conr., the False Mya, is 

 found at various places all along the coast. The 

 shell is elliptical, slightly gaping, nearly smooth, 

 though sometimes marked with faint lines. The 

 sinus is small or obsolete, and the right valve is 

 provided with a large, spoon-shaped hinge-tooth, 

 on which is the ligament. The shell is rather thin, 



whitish, with an ashy 

 epidermis; its length 

 is an inch or a little 

 more. 



Figure 78 gives us 

 a good idea of Platyo- 

 don cancellatus^ 

 Conr., the Flat- 

 toothed Clam. It closely resembles the Mya, but its 

 broad hinge-tooth is not so large; moreover the valves 

 are much thicker and firmer, and are greatly bulged. 

 The shell is white or gray, and the length is two or 



Fig. 78 



