THE NAUTILUS. 



39 



straighter on the basal line. Three specimens were obtained, one 

 adult, which is probably a male, and two young shells. The latter 

 are very different from young gracilis, having the epidermis well 

 projected around the border of the shell, and the outlines of the 

 adult state. 



To help commemorate the memory of one who has given nearly 

 a life work towards perfecting the history of the humble clam, I 

 name this in honor of Chas. T. Simpson of the National Museum. 

 Types in my own collection. 



