380 ZOOLOGY. 



PECTEN YENTRICOSUS. 



Peclen ventricosus, Sows. Thes. No. 19, pi. 12, f. 18, 19, 26. 

 Peden tumidus, SOWB. Proc. Zool. Soc. London, p. 109, 1852 ? 

 Hob. Upper California; Dr. Trask. San Diego; Mr. Cassidy. 



Family M Y T I L I D M . 

 MYTILUS EDULIS. 



Mytilus edulis, LINN., LAM, GOULD, MIDD., CARPENTER. 

 Hob. Shoalwater bay; Dr. Cooper. 



&quot;The common mussel of Europe and our own eastern coasts is found in Shoalwater bay in 

 equal abundance, and presenting the same variations in color and markings as there. It is 

 also common in the estuaries along the whole coast, and to the head of Puget Sound. They 

 are eaten by the Indians, but less used than the large clams so abundant in the same places. 

 I have also seen a very severe case of urticaria caused by eating them, probably from swallow 

 ing the beard. The same effect is sometimes observed in Europe and the United States.&quot; C. 



MYTILUS CALIFORNIANUS. 



Myiilm Californianus, CONR. Journ. Acad. Philad. VII, p. 242, pi. 18, f. 15. CARPENTER, Rep. p. 309. 

 Hab. Puget Sound, Port Townsend; Dr. Suckley, Mr. Gibbs. Upper California ; Dr. Trask. 



This shell ranges from California, northward, to the Straits of Fuca, and numerous specimens 

 have been collected and sent to the Smithsonian Institution from various localities along the 

 coast. Among them are some of all the various sizes, up to nine and a quarter inches long, 

 but all exhibiting the peculiar marks described by Mr. Conrad. These characters are less 

 obvious on the old and overgrown individuals, as might be expected, but, according to my 

 observations, can always be traced. 



MODIOLA CAPAX. 



Modiola capax, CONRAD, Journ. Acad. Philad. VII, p. 242. GOULD, CARPENTER, Rep. p. 309. 

 Hab. Straits of Fuca ; Mr. Gibbs, Dr. Cooper. 



&quot;Not a common species in this locality.&quot; C. 



MODIOLA FLABELLATA. 



Modiola Flabdlata, GOULD, U. S. Expl. Exped, Moll. & Shells, p. 453, fig. 561. IB. Proc. Bost. Soc. Ill, 343. 

 Hab. Straits of Fuca and Puget Sound ; G. Gibbs, esq. 



This is a much larger and very different shell from M. brasiliensis, so common at Panama, 

 with which Mr. Carpenter supposes it to be synonymous. (Vid. Carp. Report, p. 210.) 



LITHODOMUS. 



A fine large species, unlike any described from this region, though approaching in some 

 particulars L.fakatus, GOULD, was found in rocks near the mouth of the Umpqua river, Oregon, 

 by Dr. Yollurn, U. S. A., and sent to the Smithsonian Institution. 



