334 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



Oedee DOCOGLOSSA. 



Suborder ABRANOHIATA. 



Family LEPETIDiE. 



Genus LEPETA Gray. 

 Lepeta Gray, P. Z. S. 1847, p. 168.— Dall, Am. J. Couch, v, 1869, p. 140. 



Subgenus Lepeta Dall ex Gray. 



Lepeta Dall, Mon. Fam. Lepetidae, Am. J. Concli. v, 1869, p. 141. 



Lepeta caeca. 



Patella cwca'o. F. Muller, Prodr. Zool. Dau. 1766, p. 237; lb. Zool. Dan. i, 



p. 12. 

 Lepeta caca Gray, P. Z. S. 1847, p. 168.— DaU, 1. c. p. 141, pi. 15, f. 4. (Type.) 



Rah. — In Alaska, in 23 fathoms, off the Sea Horse Islands, near 

 Point Barrow, Arctic Ocean north from Bering Strait (Smith! 3 

 specimens). Elsewhere, northern seas of Europe and Eastern North 

 America generally, 10-100 fathoms (Sars); Massachusetts Bay north- 

 ward, in America. In Europe northward fiom Danish waters ; on the 

 Norwegian coast; the Hebrides, etc. 



This species has not been found, though reported, erroneously, south 

 from Bering Strait on the Pacific side. Such references refer to L. {0.) 

 concentrica. Jeffreys found it in six hundred and ninety fathoms off 

 Holsteinborg in Greenland, and it ranges from that depth to a few 

 fathoms. That it has a curved, nearly spiral, deciduous nucleus when 

 very young, was announced by me in 1869, and is confirmed by Dr. Jef- 

 freys in his Eeport on the MoUusca of the Valorous Expedition. It is 

 the Patella Candida of Couthouy, P. cerea of MoUer, and probably the 

 Lepeta FranTdini of Gray MSS. 



Subgenus Cryptobranchia Dall ex Midd. 



Cryptohrancliia Midd. (pars), Sib. Keise, p. 183, 1851. — Dall, Mon. Lepetidae, 1. c. 1869, 

 p. 143. 



The name CryptobraticMa was previously used by Gray, Fleming, and 

 Deshayes for different groups of mollusks of family or greater value, but 

 has in none of these cases been used or adopted by other naturalists, and 

 hence was not preoccupied for the group of Middendorf. 



Cryptobranchia concentrica. 



Patdla (Cryptobranchia) cwca, var. f3 concentrica, Midd. Sib. Reise, p. 183, pi. 



xvi, f. 6, 1851. 

 Cryptohrancliia concentrica Dall, 1. c. p. 143, pi. 15, f. 2 a-f. 

 Lepeta ccecoides Cpr. Snppl. Rep. Br. As. 1833, i)p. 603, 651. 



Hah. — North Japan, Stimpson! Schrenck!, eastward throughout the 

 Aleutians, along the southern coast of Alaska (Dall!), British Columbia 



