— 37 — 



Hmnl)oldt Bay at least, and inland. A heavy valve without diseolora- 

 tions was recently valued at fifty cents. 



It is improbable that any further development of an industry based 

 on this clam is to be expected. It is less hardy and of slower growth 

 than Mya and hence less able to withstand excessive fishing. It is 

 not a species as important to local inhabitants and tourists as it is to 

 the commercial diggers in Humboldt Bay. 



Between San Francisco and Santa Cruz occasional Washington clams 

 are found in the sheltered coves but no valuable beds are present. In 

 Elkhorn Slough emptying into Monterey Bay there is a more important 

 bed. Here they are found mixed wath the gaper (SchizotJtaerws) by 

 which the.v are far outnumbered. No further beds of note occur until 

 Morro Bay is reached when the.y are found, though less al)undantly 

 than the gaper. In both these latter localities as well as farther south 

 only Saxidomiis nuttalli was identified. 



Shells were obtained from the beaches between Point Conception 

 and Ventura and a single small specimen, apparently the young of 

 this species, was found living on an old pile used as a buoy in Santa 

 Barbara Bay (C. L. H.). Although between Santa Barbara and Santa 

 Monica the beds were largely destroyed by the great storm of 1915, 

 small numbers continue to exist, but at no point do they flourish in 

 sufficient numbers to justify commercial digging. In False Bay, near 

 San Diego, conditions remain unchanged, and the Washington clam 

 is present. The beds, how:ever, are not extensive and the yield is 

 gradually growing less according to the reports of several observers 

 (H. H.). 



It can not be said, therefore, that the soutliern AVashington clam is 

 of commercial importance at present, although it contributes to the 

 stock available for casual diggers. 



HARD-SHELL COCKLES 



Chiofic fliictifraiia Sowerby 



Plate 9, figure 1 



Ch'ioiic iindatella Sowerby 



Plate 9, figure 2 



Chione succiiicta Valenciennes 



Plate 9, figures 3 and 4 



Description — These three species may conveniently be treated 

 together as they differ but little, are often fonnd together and are all 

 equally edible. All are relatively small, measuring from two to two 

 and a half inches in length, compact and rounded in outline, with 

 firm heavy shells and short united siphons. The differences are 

 chiefly in surface markings, as may be seen from the figures. Chione 

 fiuctifraga reaches the largest size, it has no lunule or heart-shaped 

 depression just in front of the hinge and in it the radiating ribs are 

 most conspicuous, being more prominent than the concentric growth 

 lines on the siphonate or posterior end of the shell. The pallia! sinus 

 is larger than in the other species and sharply triangular instead of 

 rounded. In both Chione undatella and Chione succincta there is a 



