Vol. 32, pp. 249-252 December 31, 1919 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



NEW SHELLS FROM THE NORTHWEST COAST. 

 BY WILLIAM HEALEY DALL. 



The following forms are included by name in my forthcoming 

 summary of the fauna of the Northwest coast and it becomes 

 necessary to validate these names by descriptions. 



Leda lomaensis, new species. 



This form is closely related to L. minuta Fabricius, and I have hesitated 

 to give it specific rank, but it differs from that species by the following 

 characters: the shell is thinner and more compressed; the escutcheon is 

 narrower and longer and less emphatically impressed; the sculpture rises 

 in sharp thin low lamellae, especially on the posterior area, which contrast 

 with the thicker, blunter and more irregularly distributed ridges of L. 

 minuta. There are about eight large and seven crowded small anterior 

 teeth, a narrow oblique resilifer and about twenty, nearly all well developed 

 posterior teeth. Length 13.5; height 6; diameter 4 mm. The low incon- 

 spicuous beak is five millimeters behind the anterior end. U. S. N. Mus. 

 Cat. No. 208,872. U. S. Fish Commission station 4339, off Point Loma, 

 California, in 241 to 369 fathoms, muddy bottom. 



Lucinoma annulata densilirata, new variety. 



The typical L. annulata has the concentric sculpture rather regularly and 

 widely spaced; this variety has it closely crowded and less lamellose, giving 

 a different aspect to the shell, which otherwise does not differ from the typi- 

 cal annulata. Length 54; height 50; diameter 25 mm. U. S. N. Mus. Cat. 

 No. 108,819. Harbor of Sitka, Alaska, at station 92, in ten fathoms, mud 

 and shell, W. H. Dall. 



Venericardia nodulosa, new species. 



Shell small, rotund, inflated, solid, creamy white, with 13 to 15 radiating, 

 strong, transversely nodulous ribs ; the surface is also concentrically finely 

 lineated in the interspaces which are narrower than the ribs; the beaks are 

 prominent, there is a lanceolate small lunule in front of them, but the es- 



63— Proc. Biol. Soc. Wash., Vol. 32, 1919. (249) 



