Z THE NAUTILUS. 



These were obtained from some point on the shore of Soi.oma county 

 in the neighborhood of Bodega, the exact locality unknown. 



The Indians, Wintuns and Pomos, who formerly inhabited the 

 general region bordering this part of the coast, collected and dried 

 great quantities of the meats of this species, which formed an im- 

 portant part of their food supply, and they also made their disk- 

 shaped beads and money, hawock, out of the shells. 



Harford's 1 Alaska collection contained examples of $'. Nuttallii, 

 from Kodiak Island, Sitka, Carter's Bay, and Port Simpson. Ball's 

 voluminous Alaskan notes when published will, probably, show that 

 it is generally distributed throughout the Alaskan region. At San 

 Pedro in the south, it occurs in gravelly mud and sand, associated 

 with Tapes laciniata, a sharply sculptured species belonging to a 

 genus that like Saxidomus is without a representative on the At- 

 lantic; coast. S. Nuttallii is ordinarily a much coarser sculptured 

 shell than S. drains, and as would be inferred when its wide distri- 

 bution and great abundance are considered, varies greatly in propor- 

 tion of length to breadth and both of these to thickness. The sculp- 

 ture, varies according to the local character of the ground it inhabits. 



There are other features worthy of notice ; among these the hinge 

 cartilage, etc., and the adductors, the mechanism by which the valves 

 are opened and closed, which is exceedingly conspicuous in Soxldo- 

 mvs as compared with Tivela crassatelloides, as will be s en at a glance 

 when individuals of the two forms, of the same size, are placed side 

 by side. 



Following Ball's analysis of the so-called cartilage, 2 which he says 

 "is not a cartilage, and which is frequently spoken of as 'ligament,' 

 or ' internal ligament,' [there is] a great need of a distinctive 

 name, and I propose that of ' resilium,' which clearly indicates its 

 function ;" the term ligament being used for the upper or external 

 portion or member, which operates by pulling, while the resilium or 

 inner portion may be said to operate by causing a rebound when 

 pressed, so resisting the closing of the valves when they are open ; 

 thus these two parts or members act reciprocally, each assisting in 

 its special way in opening the valves. The function of the adductor 



1 Shells collected by the U. S. Coast Survey Expedition to Alaska in the year 

 1867 ; Proc. Cal. Acad., Dec. 2, 1867. 



?Trans. Wagner Free Institute of Science, Vol. 3, Part III, March, 1895. 



