150 AMERICAN JOURNAL 



it as new. It was sent by the Rev. I. Rowell, of San Francisco, 

 to the Smithsonian Collection, of which it forms a part (No. 

 24108), and was erroneously labelled by him as from Puget 

 Sound. The parasites show its true locality to have been from 

 the coast of Middle America. 



CYAMIIDiE. 



TURTONIA OCCIDENTALIS, n. S. 



? Turto?iia minuta, Gld., as from Bering Strait. 



Shell subtrigonal, slightly inequilateral, small and smooth. 

 Color purplish ; lighter, with a yellowish epidermis, toward the 

 margin, especially anteriorly. Interior dark purple in the mid- 

 dle of the valves, margins lighter, dark brown above and behind. 

 Hinge-line and ventral margin roundly arcuate, ends rounded, 

 anterior a little shorter and smaller. Epidermis yellowish brown, 

 polished, with rather strong lines of growth at intervals. Urn- 

 bones rather prominent, usually eroded. Shell a little tumid. 

 Teeth strong, apparently three cardinals in the left valve, with 

 the posterior dorsal hinge margin folded in making a strong 

 tooth-like lamella. Right valve with one long and one triangular 

 cardinal tooth, and a posterior lamella as in the other. Pallial 

 line simple, lightly waved near the posterior muscular scar. 

 Anterior scars two, perfectly separate and distinct, the upper 

 triangular, slightly smaller. 



Lon. -2. Alt. -16. Diam. -1 in. 



Habitat. Plover Bay, Eastern Siberia, abundant in the roots 

 of fuci. Dall., 1865 and 1866. 



Although this species differed in its larger and more trigonal 

 and shorter form from all the figures of T. minuta, I felt un- 

 Avilling to describe it, until receiving some Atlantic specimens 

 the matter was placed beyond a doubt by the comparison. It is 

 four or five times the size of the T. minuta, much shorter pro- 

 portionally and more equilateral, less compressed and darker 

 colored. The teeth also differ slightly. I have not adopted the 

 genus Cyamium as it seems to be in dispute. I am glad to be 

 able to fully confirm the observations of Mr. Jeffreys (Brit 

 Conch., ii, p. ) in regard to the siphon and foot. The liga 

 ment is wholly external. The double anterior scars are inter- 

 esting. 



CARDITID^. 



Genus ASTARTE, Sowerby. 

 Astarte, Sby.. Min. Conch., t. 167, 1816. Type A. Dan- 

 moniensis. Mont. 



