16 



WEST COAST SHELLS 



Figure 49 represents a very large, heavy shell, 

 probably the largest of all the Venus shells. It is 

 now known as Tivela stultorum^ Mawe, the Great 

 Tivela. Of course that is not a correct translation 



Fig. 49 



of the Latin; that you may make for yourselves, 

 avoiding the joke. It used to be called Pachydesfna 

 crassatelloides^ and it has also had a good many 

 other names, all of which have been duly considered 

 at the Smithsonian Institution, and the one most 

 entitled to permanence has been selected to remain. 

 The name "tivela crassatelloides, Conrad, is, how- 

 ever, now considered to be the correct one. 



The specimen figured above was over five inches 

 in length, and weighed over a pound, without the 

 animal. The valves are very thick and heavy, even 

 to their edges, which are smooth and finely rounded. 

 The hinge-teeth are strong, the heavy ligament ex- 



