184 SHELLS OF SAN PEDRO BAY—WILLIAMSON. 
Family ANATINIDZE. 
Genus PERIPLOMA Schumacher. 
Periploma planiuscula Sb y. (P. argentaria Conr., of authors.) 
Hight or ten living shells. Single valves common. For notes on the 
> 2 D 
specific name of this species, see Stearns’s “ West American Shells.” 
Proc. U. S. Nat. Mus., x11, No. 813, page 223. 
Periploma discus Stearns. 
This new shell, found in San Pedro Bay, is described by Dr. Stearns, 
as above mentioned, p. 222, pl. XVI, figs. 1, 2. 
The first specimen was found by Mrs. D. Garlick, and soon after 
Miss Shepard and Mrs. Trowbridge found others in the bay. Since 
that time seven or eight shells have been collected. 
Genus THRACTIA Leach. 
Thracia curta Conr. 
Rare; in the bay; dead. 
Genus LYONSIA Turton. 
Lyonsia californica Conr. 
Three or four dead shells. One live example in the drift at Rattle- 
snake Island, found by Mrs. Emma King. 
Family SOLENID 2. 
Genus SOLEN Linné. 
Solen ensis Linné, var. minor Conr. 
Several collected at Long Beach. (W. H. D.) 
Solen rosaceus Cpr. 
Washed ashore after storms. 
Solen sicarius Gld. 
Four or five. 
Genus TAGELUS Gray. 
Tagelus californianus Conr. (Solecurtus californianus Conr.) 
Not uncommon in the Bay. ‘The generic name of the Solecurtus 
californianus and S. subteres, of Carpenter’s list, is Tagelus. The true 
Sclecurtus is a different shell.” See Bulletin U.S. Nat. Mus. No. 37, 
p. 938; also, Dall, Report on Albatross Mollusca in Proc, U.S. Nat. Mus., 
Vol. XII, p. 243. 
Tagelus californianus var. subteres Conr. 
Found with the former. Epidermis, when present, very dark. 
