454 PROCEEDINGS OF THE ACADEMY OF [1896. 



Williamia peltoides Carpenter. 



Nacella peltoides Carpenter, Ann. Mag. Nat. Hist., 1864, i, p. 474, No. 15; 

 Suppl. Kep. Brit. Assoc, 1863, pp. 418, 545. 



Nacella sttbspiralis Carpenter, Proc. Cal. Acad. Sci., iii, p. 213, 1866 ; Suppl. 

 Rep. Brit. Assoc, 1863, pp. 612, 640. 



Siphonaria [Liriola) peltoides Dall, Am. Journ. Conch., vi, p. 37, 1870; 

 Journ. de Conchyl., xxvi, p. 68, Jan., 1878. 



Anisomyon peltoides Dall, Journ. de Conchyl., xxvii, p. 288, Oct., 1879. 



A'acella subspiralis Wimmer, Sitzb. k. Akad. Wiss., Wieri, Ixxx, p. 41, 

 1879. 



Siphonaria ( Williamia') peltoides Stearns, Proc U. S. Nat. Mus., xvi, p- 

 584, 1893. 



Chatham, Charles and Hood Islands, dead on the beach, Dr. 

 llabel ; northward to Panama, Mazatlan, Cape St. Lucas, San Diego 

 and the Santa Barbara Islands, California. The variety vernalis 

 Dall, which will require to be specifically separated from peltoides, 

 extends from the Santa Barbara Islands northward to Monterey, 

 Purissima, Lobitas and Crescent City, California. It is much larger 

 than either of the others. 



The Nacella subspiralis and peltoides of Carpenter are undoubt- 

 edly conspecific with the Galapagos shell, which from its perching 

 habit on fronds of Laminaria may be widely distributed by ocean 

 -currents. The well known Ancylus Gussoni of Costa belonging to 

 the South European fauna is congeneric, and from the shells alone 

 it is doubtful if the species could be separated. The W. Krebsii of 

 Morch is extremely similar, and it is possible that all three should 

 be specifically united, but until the anatomy has been compared it 

 is probably best to keep them distinct. I figured the dentition and 

 jaw of W. vernalis and W. Gussoni in the Journal de Conchy liologie 

 in 1878 and 1879, showing specific differences between them, but 

 the West Indian and West American tropical .forms have not yet 

 been examined. 



M. Cossmann has described a species, W. Raincourti, from the 

 Eocene of Chaumout, Paris Basin, which differs from the recent 

 species in being radially striate ; this seems to partially bridge the 

 gaj) between the latter and the upper Cretaceous Anisomyon. 



Onchidium Leslie! Steams. 



Onihidiitm Lesliei Stearns, Nautilus, VI, p. 87, Dec, 1892; Proc. U. S. 

 Nat. Mus., XVI, No. 942, p. 383, pi. 51, figs. 2, 3, 1893. 



Living between tide marks on Charles and Albemarle Islands, U. 

 S. Fish Commission. 



Dr. Stearns' description is as follows : 



" Form rounded ovate, nearly as broad as long. Dorsum coria- 

 ceous, nearly black, shiny, closely irregularly reticulated with finely 



