NO. 2002. DIAGNOSES OF NEW PACIFIC SHELLS— DALL. 593 



concentric threads, forming nearly square equal reticulations, about 

 four to a square millimeter; the intersections are slightly prominent 

 on the disk and more or less minutely spinose on the ends of the 

 valve; beside these the entire valve is sculptured with minute equal 

 radial lines, about six to a reticulation; the interior of the valve is 

 glassy, the sculpture showing through. The flatter valve has similar 

 sculpture, with a narrow smooth submargin, a ctenolium of five or six 

 free teeth, a moderately deep byssal notch and five imbricated rays 

 on the ear above the fasciole of the notch. 



Height, 35; length, 34.5; diameter, 6.0 mm. 



Off Santa Barbara, California, in over 500 fathoms, muddy bottom. 

 Cat. No. 267169, U.S.N.M. 



A neat species, remarkable for the even character of its reticula- 

 tion and its uniformity over both valves. 



CUSPIDARIA SUBGLACIALIS, new species. 



Shell large for the genus, chalky, with a coarse dehiscent olivaceous 

 periostracum ; equi valve, nearly equilateral. Beaks nearly in the 

 center of the shell, anterior dorsal margin arcuately descending, ante- 

 rior end of shell ovately rounded; posterior slope straight, or slightly 

 distally recurved, with a short compressed distally gaping rostrum, 

 terminally subtruncate; base arcuate, somewhat patulous below and 

 behind the beaks, incurved at the beginning of the rostrum; hmge in 

 the left valve with a small obliquely backwardly directed chondro- 

 phore; in the right valve there is also a strong lamina parallel with the 

 dorsal margin and separated from it by a groove which receives the 

 edge of the opposite valve in closing; beaks opisthocoelous, incon- 

 spicuous. Height, 24; length, 39; diameter, 20 mm. 



Off the Califomian coast in deep water. Cat. No. 265904, U.S.N.M. 

 Nearest to C. glacialis M. Sars, from which it differs in the less promi- 

 nent and less posterior beaks and less recurved rostrum. 



PSEPraDIA CYMATA, new species. 



Shell small, white, solid, rounded triangular, with inconspicuous, 

 somewhat anterior beaks, the lunule and escutcheon very feebly 

 indicated; surface with fine concentric but not perfectly regular low 

 threadlike sculpture; periostracum yellowish, rather coarse; hinge 

 of the genus; inner margins smooth, interior disk polished, the pallial 

 sinus small, ascending, the inner extreme bluntly rounded; muscular 

 impressions distinct, ligament small and weak. Height 5.5; length 

 6.0; diameter 2.5 mm. 



Near Cerros Island, Lower California, in shallow water. Cat. No. 

 266158, U.S.N.M. 



This has nearly the profile of P. lordi Baird, but is much less 

 inflated, and the surface is concentrically sculptured instead of smooth, 

 80459°— Proc.N.M. vol.45— 13 38 



