379 



Dr. Stanton has identified with Meretrix arata, Galjb, and kindly loaned 

 to the writer. The original description of the sculpture of M. arata is 

 rather misleading. According to Mr. Gabb, its surface is ' ornamented 

 by regular, concentric, acute impressed lines,' whereas, in the writer's 

 judgment, it would be much more correct to say by small, concentric, 

 rounded ribs, with very narrow furro>vs between them " (1896, op. cit. 

 supra. ) 



A few additional specimens of this species were collected at the 

 Sucia Islands by Dr. Newcombe 'in 1894 and 1896. A small but 

 perfect left valve, some sixteen millimetres long, collected at Texada 

 Island, by Mr. Harvey, in 1901, seems to be intermediate in its character 

 between M. yiitida and JI. arata. On and immediately around the umbo 

 the surface of this specimen is minutely and regularly ribbed concentri- 

 cally, but; below, fully two-thirds of the surface are only striated in the 

 same dii'ection. 



Cyprijueria le\s, Whiteaves. 



Crprimeria hns, Whiteaves. 1879. This volume, pt. 2, p. 152, pi. 17, figs. 15 and 15 a ; 

 but not Meretrix lens, Gabb, 1864, which is probably not a Ci/primeria. 

 " White. 1889. Bull. U.S. Geological Surv., No. ^1, p. 42.. 

 " " Whiteaves. 1896. Trans. Royal Soc. Canada for 1895, Second Series, 



vol. I, sect. IV, p. 125. 



" Shell compressed convex, moderately inflated, ovately subcircular in 

 marginal outline, and nearly as high as long ; posterior side a little 

 longer, and in some specimens rather more narrowly rounded than the 

 anterior ; basal margin broadly convex ; superior border descending 

 rapidly and obliquely in front of the beaks, gently convex and slightly 

 prominent immediately behind them, thence curving gradually downward 

 to the posterior end, beaks placed a little in advance of the midlength, 

 small, depressed, appressed and curved forward. No definite nor dis- 

 tinctly margined lunule, and apparently no well defined escutcheon. 



" Test rather thick, its surface polished and marked with numerous very 

 fine and closely disposed concentric strife, also with four or five distant 

 and coarser linear concentric grooves or periodic arrests of growth. 



" Hinge with two cardinal teeth and one lateral tooth in the left valve. 

 The two cardinal teeth are transverse and divergent, the anterior one 

 being thick and excavated in the middle, but not bifid. The lateral 

 tooth, which is thin and feebly developed, is partially separated from the 

 cardinal fulcrum by a narrow shallow groove. Anterior muscular impres- 

 sion large and subovate ; posterior muscular scar, pallial line and hinge 

 dentition of the right valve unknown. 



