58 



WEST COAST SHELLS 



Fig. 27 (*) 



and can easily be identified by the strong ribs which 

 seem to radiate from one corner. The color is 

 brownish-white, the inside being sometimes stained 

 with purple. It may occasionally be found alive, 

 attached to stones, while dead specimens are often 

 washed up with the gravel on the beach. 



In Figure 27 we 

 have a picture of the 

 inside of the right 

 valve of Calyptogena 

 pacifica^ Dall, the 

 Pacific Calypto. The 

 outside of the shell is 

 nearly smooth, being 

 marked only by lines 

 of growth, though the white exterior may be cov- 

 ered with a thick, greenish epidermis. It was 

 dredged off Dixon Entrance, Alaska, in 322 fathoms 

 of water. You will notice in this shell, as in all 

 belonging to this great family, that the pallial line 

 is entire, showing that the creatures do not burrow 

 deeply in the mud at the bottom of the sea. 



Figure 28 gives a good ex- 

 ternal view of Venericardia 

 alaskana^ Dall, the Alaskan 

 Venus-heart. It was collected 

 at Nunivak Island, in Bering 

 Sea. Notice the strong ribs, 

 the lines of growth, and the 

 artistic outline ol the whole 

 shell. 



Fig. 28 (*) 



