212 MOLLUSC A OF BERING ISLAND. 



This fine, lar^e form, which, from its colossal size at Atka Island and 

 Kyska, I have distributed for ten years under the name above given, is, 

 to my mind, closely related to sitJcana, from which it differs in its larger 

 size, smooth surface, and tendency to spiral bands of white and dark- 

 brown. Until the whole group can be carefully studied and dissected, 

 it would be foolish to be dogmatic in opinion about them, but I have 

 not been able from a study of about a bushel of the shells merely, to 

 indentify this form with tenebrosa, or find any special likeness in it to 

 obtusata. 



LACUNA. 



Lacuna vincta Montagu. 

 Bering Island, Grebnitzki. 



Subgenus HALOCONCnA. 



LacuneUa Dall, Proc. U. S. Nat. Mus. , VII, p. 344, 1884. Not of Deshayes. 

 , i«c«na?7a Dall, in errata, 1. c, J), viii. Not of Courad. 



The writer having examined the last uomeuclator and finding no 

 mention of LacuneUa, and totally forgetting Deshayes's use of the name, 

 was»':"areless enough to look no further, and his erratum, prepared at 

 the >^'' t mdment and without time for an exhaustive search, was as 

 unforamate as his first venture. The present name is substituted with 

 some ai)prehension, but not until after a careful and thorough search. 



Natica clausa Brotleiip and Sowerby. 



Bering Island, Vega Expedition. 



Aurivillius makes this = JSf. gronlandica (Beck) Moller, though he 

 gives Holler's species subsequently, and speaks of it as having a horny 

 operculum. The first mention probably should be septcntrionalis (Beck) 

 Moller, which is identical with clausa, but applied thirteen years later. 



Turritella (Tachyrhynchus) erosa Couthouy. 



T. erosa (Couthouy) Aurivillius, 1. c.,^. 322, pi. 12, fig. 7 ; pi. 13, fig. 17. 

 T.polaris Beck, Moller. Index, Moll. Gronl., 1842. 



Bering Island, dredged in 65 fathoms, Vega Expedition. 

 This species, common to the Arctic seas, is very much larger in the 

 Arctic Ocean than in the Aleutians or on the New England coast. 



Cerithiopsis stejnegeri Dall. 

 Bering Island, one fine specimen, Grebnitzki. 



Tritonium oregonense Eedfield. 



Triton oregonense Redfield, Ann. Lye. Nat. Hist. N. Y., IV, p. 165, pi. XI, figs. 2c, 



2b (immature), 1846 (Str. of Fuca). Gould, Expl. Exp., Shells, p. 241, 1852. 

 Fustis oregonensis " Say" Reeve. Conch. Icou., IV, Mon. i^i/sws, figs. Glo-b, 1848 



(North America). 

 Tritonium cancellatum Midd.,Mal. Ros.,II, 165, pi. Ill, figs. 1-4, 1849. Not oi' 



Lamarck. 



