184 



SAXIDOMUS. 



shell is oval, and it is quite full and strong. The 

 pallial sinus is very deep, and the shell is white, with 

 some brown markings around the hinge-area. Radial 

 lines are very faint, but lines of growth are fine, 

 regular and strong. The hinge-teeth are very dis- 

 tinct, indicating a strong, powerful shell. Its length 

 is from two to several inches. 



Saxidomns Nuttallii, Conr., Nut-tall'-i-i, Fig. 157. 

 The shell of this species is strong and heavy, and is 

 marked by numerous rough, irregular, concentric 

 ridges. The interior of the shell is white, and the 

 thickened portion below the huge external ligament 

 is translucent like agate. The pallial sinus is very 

 deep, and the posterior end of the shell is slightly 

 gaping. Color brownish white, length four inches 



