454 PROCEEDINOS OF THE NATIONAL MUSEUM. vol.49. 



LYONSIA PUGETENSIS Dall. 



Lyonsia jmgetensis Dall, Proc. U. S. Nat. Mus., vol. 45, No. 2002, p. 595, June, 

 1913. 



Distribution. — Chignik Bay, Alaska Peninsula, and east and south 

 to Puget Sound, Washington. Cat. No. 249966, U.S.N.M. Type 

 locahty near Queets River, Washington. 



This is probably the largest described species of the genus. An 

 immature specimen was used as a type for the description, because it 

 was perfect and not eroded. It showed nothing which could be 

 considered as a lunule or escutcheon. Adult specimens measure 

 52 mm. long by 28 mm. high and 16 mm. in diameter. 



LYONSIA PANAMENSIS DaU. 



Lyonsia panamensis Dall, Bull. Mus. Comp. Zool., vol. 43, No. 6, Oct. 1908, 

 p. 427, pi. 18, fig. 12. 



Distribution. — Type locahty, Gulf of Panama, 556 fathoms. Cat. 

 No. 110584, U.S.N.M. 

 This is closely aUied to L. arenosa and to the following species. 



LYONSIA FRETALIS, new species. 



Shell small, thin, white, hardly pearly, subdonaciform, covered 

 with a rather strong, smooth, brownish periostracum ornamented 

 with sparse, distant, elevated, radial hues, about a dozen in number; 

 beaks prominent, opisthogyrate, close to the anterior end; anterior end 

 broadly rounded, posterior end narrower, rounded blmitly, not trun- 

 cate; no lunule or escutcheon; periostracum extending sHghtly 

 beyond the calcified margins; mterior slightly pearly, pallial line 

 with (for the genus) a rather well-marked smus; hinge feeble, the 

 resihum parallel with the margin, the hthodesma elongate-quadrate. 

 Length, 10; height, 7; diameter right valve, 4, left valve, 3 mm.; 

 beaks behind the anterior end, 2.5 mm. 



Distribution. — Type locahty. Straits of Magellan, in 20 fathoms. 

 Cat. No. 96196, U.S.N.M. 



This species has close relations with the Arctic L. arenosa. 



I have not seen the Anatina cuneata of Gray, 1824, which has 

 generally been referred by authors to Entodesma, but Hanley's copy 

 of the original figure m his edition of the Index Testaceologicus, 

 resembles a typical Lyonsia rather than an Entodesma. E. cMlense 

 Phihppi which has been imited with it is certainly a very different 

 shell, as is Entodesma pictuin Sowerby, although both were referred, 

 in my Report on Peruvian Shells (1909), on the authority of other 

 authors to cuneata Gray. The Lyonsia patagonica of Orbigny in the 

 Voyage dans I'Am^rique Meridionale, is from the Atlantic coast, at 

 the Bay of San Bias, and is probably an Entodesma; his L. alvarezii 

 from the same locality a true Lyonsia, but unlike either of the Pacific 



