NO. 2116. ANATINACEA FROM WEST COAST OF AMERICA— BALL. 453 



LYONSIA ARENOSA MoUer. 



Pandorina arenosa Moller, Index Moll. Gronl., p. 20, 1842; Beechey's Voy. 



to the Pacific, pi. 43, fig. 3, 1839 (not named in the text). 

 Lyonsia gibbosa Hancock, Ann. Mag. Nat. Hist., vol. 18, 1846, p. 238, pi. 5, figs. 



11, 12. 

 Anatina striata Gray (not Montagu), according to Hancock, Ann. Mag. Nat. Hist., 



vol. 18, 1846, p. 238 (not in Appendix to Ross's Voyage). 

 Lyonsia fiabellata Gould, Otia Conch., p. 162, 1861. 

 ILyonsia ventricosa Gould, Otia Conch., p. 161, 1861. N. Japan. 

 Osteodesma aeruginosa Mighels (ubi ?). 

 Lyonsia arenosa var. sibirica Leche, Vega Exp., vol. 3, p. 439, pi. 22, figs. 3, 4, 



1882. 



Distribution.— GreeTilajid and Arctic Sea. On the Pacific from the 

 Arctic south to Japan and the Okhotsk Sea on the west, and to the 

 Aleutian chain and Kadiak Island on the east. Cat. No. 223476, 

 U.S.N.M. 



This yellowish, short and solid species is well distinguished from 

 any of the others. Leche's variety is more elongate than the normal 

 type. A full series of the form from north Japan would doubtless 

 make clear the identity of Gould's ventricosa with the Arctic species. 



LYONSIA GOULDn, new name. 



Osteodesma nitidum Gould, Mex. and Cal. Shells, p. 17, pi. 15, fig. 6, May, 1851. 

 Not Mya {=Lyonsia) nitida Fabricius, 1798. — Osteodesma nitidum Gould, 

 Otia Conch., p. 187, 1861. Type locality, Santa Barbara, California. 



Distribution. — San Francisco Bay, California, and south to Point 

 Abreojos, Lower California. Cat. No. 131739, U.S.N.M. 



This small, slender, and very pearly species is different both in 

 form and distribution from the preceding. 



LYONSIA CALIFORNICA Conrad. 



Lyonsia califomica Conrad, Joum. Acad. Nat. Sci. Phila., vol. 7, p. 248, pi. 19, 

 fig. 20, 1837. 



Distribution. — Puget Sound, Washington, and south to Todos 

 Santos Bay and the Coronado Islands, Lower California. Cat. 

 No. 253111, U.S.N.M. 



This white and pearly species takes much the same place in the 

 fauna that L. coruscans Scacchi does in the South European fauna. 

 It is the most common species on the Calif ornian coast and is usually 

 more or less arcuate and very pearly. A variety with nearly cylin- 

 drical form without arcuation from San Francisco Bay has been 

 named by me L. var. Jiaroldi in honor of Mr. Harold Hannibal, of 

 Stanford University, and a very thin, smaller, and translucent form 

 from Catalina (type locality) and the Coronado Islands, with the 

 beaks very close to the anterior end, may be called var. nesiotes. 

 The latter may possibly, with more material, prove distinct. Cat. 

 No. 206410, U.S.N,M. 



