NO. 131-'. SYNOPSIS OF THE VENERID.E—DALL. 407 



LIOCYMA BECKII Dall. 

 Plate XVI, fig. 3. 



Lioeymti heckn Dall, Proc. Boston Soc. Nat. History, XIII, 1870, }>. 257; Am. 

 Jouru. Conch., VII, 1871, p. 145, pi. xiv, fig. 7. 



Plover Bay, eastern Siberia, at the western entrance of Bering 

 Strait. Cat. No. 163110, U.S.N.M. 



LIOCYMA VIRIDIS Dall. 



Plate XV, fig. 1. 



Lioq/ma viridis Dali., Am. Journ. Conch., VII, 1871, p. 146, pi. \iv, fig. 8. 



Kyska Harbor, Great Kyska Island, in 8 fathoms, sand; W. H. Dall. 

 Cat. No. 160904, U.S.N.M. 



LIOCYMA SCAMMONI Dall. 

 Plate XVI, fig. 1. 

 Liocyma scammoni D.vll, Am. Journ. Conch., 1871, VII, p. 145, pi. xiv, fig. 9. 



Port Simpson, British Columbia: Capt. C. M. Scammon. Cat. No. 

 163121, U.S.N.M. 



PSEPHIDIA lord: Baird. 



Plate XVI, figs. 5, 6. 



Chione lordl^Ai-RD, Proc. Zool. Soc, 1863, p. 69, pi. ii, fig. 10. 

 Psephis Jordi Carpenter, Proc. Acad. Nat. Sci. Phila. for 1865, p. 57. 



Lituya Bay, Alaska, in 8 fathoms, sand; W. H. Dall. Cat. No. 

 1630Tl', U.S.N.M. 



The specimen figured is perhaps more trigonal than usual, others 

 are slighth' more produced behind. 



PSEPHIDIA OVALIS, new species. 



Plate XVI, fig. 4. 



Shell small, white, polished, oval, subcompressed; surface with obso- 

 lete concentric threads near the anterior base, but over most of the 

 disk smooth; beaks small and very low, at about the anterior third 

 of the length; lunule elongated, extremely narrow, n«>arly as long as 

 the anterior dorsal slope; escutcheon linear or none; interior white, 

 the pallial sinus moderate, pointed; internal margin delicate h' striated; 

 hinge well developed, like that of J*, hn-di^ with three entire cardinal.^ 

 and no anterior lateral tooth. Length, 8.5; height, 6.5; diameter, 

 3.0 umi. 



