^''iVl'''] proceedings of the national museum. 185 



lata being shorter, more elevated and inflated, with the anterior part of 

 the pailial sinus confluent with the anterior muscular impression. As 

 the T. denticulata has never been figured we have thought it useful to 

 reproduce Mr. Smith's drawing, which will be found at figures 2 and 3, 

 Plate VII. 



The species is named for Miss Ida Shepard, to whom we owe the oppor- 

 tunity of examining it, one of a group of energetic collectors and students 

 of the local fauna who have recently made important additions to our 

 liuowledge of the molluscan fauna of southern California. 



Clementia subdiaphaua Carpeuter. 

 (Plate VII, Figs. 5, 6.) 



Clementia suMiaphana Carpeuter, Suppl. Rep. Brit. Assoc, 1863, pp. 602, 607, 640 ; Proc. 

 Acad. Nat. Sci. Phila., 1865, p. 56. 



Habitat: Vancouver Island, Lord; Puget Sound, Kennerly; Port 

 Etches and southward on the Alaskan coast, 14 to GO fathoms, Dall ; off 

 Drake's Bay, California, near the entrance to San Francisco Bay, dredged 

 by Mr. J. S. Arnheim in 21 fathoms, and lent for examination by Mr. J. 

 J. Rivers, University of California. 



The original specimens of this species were young and subdiaphanous. 

 Specimens collected by the writer at Port Etches in 1874 are as large as 

 Venus mercenaria, ashy and calcareous, but still relatively very thin. 

 They are usually, especially the young ones, more elongate and Callista- 

 like in form than the remarkably rounded specimen which Mr. Rivers 

 has been so kind as to lend us for examination. As this fine shell has 

 not been figured, I have taken advantage of the opportunity of putting 

 its characters on record graphically. Inside it is of a dead chalk- white, 

 with the muscular and pailial impressions polished, and also less obvi- 

 ously the border outside of them. The ligament is black and sunken ; 

 there is neither lunule nor escutcheon. The area where the lunule 

 should be is slightly more polished and compressed than the adjacent 

 surface, but has no circumscribing line. The beaks are small and in- 

 curved, so that they point away from the hinge line. The exterior is 

 white with some fortuitous rusty spots, sculptured with strong, slightly 

 irregular lines of growth. The surface between the lines has a slight 

 silky luster. The valve figured has a maximum longitude of 62.5, an 

 altitude of 58, and a diameter (excluding the teeth) of 18 millimetres. 

 The pair, of course, would have had just twice that diameter. 



The young shell is greenish, subtranslucent white, very thin, and 

 usually more elongated in proportion than the adult here figured; but 

 the forms completely intergrade. The locality whence the specimen 

 was obtained is 600 miles farther south than before reported. On the 

 other hand, Port Etches is about the same distance farther north and 

 west than any locality for the species heretofore made public. 



