Plate 51. 
Page 
igure la. Pholadidea ovoidea Gould. 212 
Bolinas. Exterior of left valve showing siphons extended. 
lb. Pholadidea ovoidea Gould. 212 
Dorsal view showing siphons extended. 
2a. Pholadidea ovoidea Gould......212 
Ventral view of an immature specimen. 
2I>. Pholadidea ovoidea Gould.212 
View of left valve of same specimen. 
3a. Pholadidea penita Conrad...211 
Bolinas. Exterior of left valve showing siphons extended. 
3b. Pholadidea penita Conrad.211 
Dorsal view. 
4. Saxicava arctica Linnaeus..-..203 
Exterior of left valve. 
5. Saxicava photadis Linnaeus.209 
Goat Island, San Francisco. 
Exterior of left valve. 
This plate is from University of California Publ. 
Vol. 14, Zoology. 
