PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 317 



opportunity of making the correction, wliich, had Dr. Cari^cntcr survived 

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



In the hiu-ry of field-work, the specimens were confounded vv'i(»h younj^ 

 T. alhus, and hence no observations on the living' animal were made. 

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

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

 tions from more noi-theru 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 occupy a space corresponding to the posterior quarter of the 

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

 ])lain and thick. The veil is plain. The muzzle is rounded, v/ith a little 

 papilla at the i^osterior corner on each side. 



Leptochiton alveolus. 



Lcptocldton alveolus (Sars MS.) Lov6n, lud. Moll. Lit. Scaiid. -p. 27, 1846. 



Not of Jeifrcys, etc. 

 Lcpidoplcurus alveolus G. O. Siirs, Moll. Reg. Arc. Nor. p. 110, t. 7, f. 3 a-i; t. 



I, f. 7 (good), 1878. 



Hah. — Bergen, Lofoten, Finmark, 150-300 f. (Sars); Gulf of St. Law- 

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

 costi Island, Whiteaves ! St. G eorge's Bank, Gulf of Maine, 150 t;athoms, 

 IT. 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. WhiteaACS. 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, dorsaliter angulata; albidii plus minusve 

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

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

 sparsim et quincuncialiter dispositis. Yalva postica sub apice concavu, 

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

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



Rah.— North Pacific Ocean, in lat. 53° 08' X, lon. 171^ 19' W., at 

 a depth of 1006 fathoms; bla(;k sand and shells. Brought up in the 

 sounding-cuj) by Capt. Geo. E. Belknap, U. S. IS"., on the sounding ex- 

 ])edition of IT. S. S. Tuscarora in 1871, bottom temperature 35°.5 F. 

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

 Sound, Kerguelen Id., Southern Ocean, in 20-00 fms., for examination 

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

 apparently identical with Capt. Belknap's species.) 



