— ;i5 — 



WASHINGTON CLAM 



Saxi^Io/iii/s 

 Plate 7, figures 1 and 2 ; plate 8, figures 1 and 2 



Other names — Butter elam ; money shell. 



Two species of Saxidomiis are recorded from California by Dall — a 

 northern form, S. giganteus, ranging from Alaska to Monterey, and a 

 southern form, 8. nuttalli, found from Bolinas Bay to San Diego. 

 The species are quite similar and some recent writers have united them 

 as mere variations of one form.* The writer, on the basis of material 

 examined, can not agree in this; the two species seem distinct but 

 aS'. nuttalli extends farther north than Bolinas Bay, being found in 

 Humboldt Bay and possibly in Puget Sound. The two species will 

 be descrilied separately but treated largely together, as they are not 

 distinguished by the diggers and are marketed together. Neither 

 are there distinctive common names for the two forms. Besides 

 Washington clam the names butter clam and money shell are used in 

 some localities. The name "Washington clam" is also applied to the 

 gaper, Schizothaenis, perhaps more justly, but its local use for 

 Saxidomiis is said to have come from its resemblance to Venus merce- 

 naria of the Atlantic coast, as noted by Indian chiefs at the time 

 certain of them were in Washington, D. C, conferring with government 

 officials. The name "money shell" came from the use of Saxidomus 

 shells of pearly appearance and unusual thickness as money by the 

 Indians of Bodega and Tomales bays. 



Saxidomus nuttalli Conrad 



Plate 7, figures 1 and 2 



This is the larger of the two species. The shell is thick and firm, 

 oval in outline and roughened on the oTiter surface by numerous 

 concentric gro\^i:h lines; within, it is white with slight touches of 

 purple, particularly about the siphonate end. The siphons are united, 

 long and completely retractile, though due to the slight gaping of the 

 siphonate extremity of the shell they can usually be seen from the 

 end. The pallial sinus is deep, corresponding to the size of the 

 siphons. 



Saxidomus giganteus Deshayes 

 Plate 8, figures 1 and 2 



The general appearance of this species is similar to that just 

 described but the shell is somewhat more circular in outline and smaller. 

 The outer surface is much less rough, the growth lines being finer and 

 lower; the white of the interior is without any tinge of purple. The 

 llesh is whiter than that of 8. nnttallk 



Habitat and habits^ — rSince essentially similar, the habits of the 

 two species may be described together. The stout shell, the moderately 



♦Packard, E. L. Molluscan Fauna of San Francisco Bay, University of California 

 Publications in zoology. Vol. iv, no. 2, p. 269, 1918; Clark, B. L. Fauna of San 

 Pablo Group of Middle California, University of California Publications, Geology, 

 Vol. viii, 1915. 



