PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 317 



oppo.'tuiiity of liuikiii!^ the eoiTcctiou, whicL, bad Dr. Carpenter survived 

 to finish his work, he wouhl undoubtedly have done himself. 



In the hiuTy of field work, the speeimens were confounded wil»h young 

 T. albus, and hence no observations on the living animal were made. 

 Had attention been drawn to it, it might, doubtless, have been obtained 

 thi'oughout the Aleutian chain, but no specimens occurred in the collec- 

 tions from more northern localities. Jeffreys states that the under edge 

 of the girdle and the soft parts are yellowish white, tinged with flesh 

 color; also that littoral specimens from Herm are larger than those found 

 in deeper water. In Alaska it has been obtained only with the dredge. 



The gills occuj>y a space corresponding to the posterior quarter of the 

 foot; there are about eight or ten on each side. The mantle edge is 

 plain and thick. The veil is plain. The muzzle is rounded, with a little 

 papilla at the posterior corner on each side. 



Iieptochiton alveolus. 



Leptochiton alveolun (Sars MS.) Loveu, Iiid. Moll. Lit. Scand. p. 27, 184G. 



Not of Jeffreys, etc. 

 Lepidopleurus alveolus G. O. Sars, Moll. Reg. Arc. Nor. p. 110, t. 7, f. 3 a-i : t. 



I, f. 7 (good), 1878. 



ira&.— Bergen, Lofoten, Finmark, 150-300 f. (Sars); Gidf of St. Law- 

 i-ence, in 220 fathoms, between Cape Eosier and the S. W. point of Anti- 

 costi Island, Whiteaves ! St. George's Bank, Gulf of Maine, 150 fiithoms, 

 F. S. Fish Com., 1872 ! 



This extra-limital species is inserted here because of its possible rela- 

 tions with the next species, and also to call attention to the addition to 

 our Northeast American fauna made by Mr. Whiteaves. It is a remark- 

 ably distinct species, and if typical examples had been examined by the 

 authors who have referred it to L. cancellatus, it would seem unlikely 

 that it would have been so referred. 



Leptochiton Belknapi. 



Leptochiton Belknapi Dall.Proc. U. S. Nat. Mus. p. 1, Jan. 1878. 



L. t. elongata, valde elevata, dorsaUter angulata; albida plus minusve 

 cinereo et nigrotincta; valvis elevatis, apicibus distinctis; mucrone cen- 

 tral! conspicuo; sculptura ut in L. alveolo, sed granulis in areis dorsalis 

 sparsim et quincuncialiter dispositis. Valva postica sub apice concava, 

 postice sinuata. Zona minima, spiculis tenuibus versus marginem mu- 

 nita. Lon. 10.0, Lat. 3.0 mm. Div. 90°. 



Hab.— North Pacific Ocean, in lat. 53° 08' N., lon. 171° 10' W., at 

 a depth of lOOG fathoms; black sand and shells. Brought uj) in the 

 sounding-cup by Capt. Geo. E. Belknai), TJ. S. N., on the sounding ex- 

 pedition of U. S. S. Tuscarora in 1874, bottom temperature 35^.5 F. 

 (Specimens obtained by H. M. S. Challenger in Balfour Bay, Eoyal 

 Sound, Kerguelen Id., Southern Ocean, in 20-()0 fms., for examination 

 of which I am indebted to the courtesy of Eev. E. J. Boog Watson, are 

 apparently identical with Capt. Belknap's species.) 



