NOKTHWEST COAST MARINE SPIELLBEARING MOLLUSKS. 93 
PLICIFUSUS ARCTICUS Philippi. 1850. 
Abb. u. Beschr. Moll., vol. 3, p. 119, pi. 5, fig. 5. 
Arctic Ocean, Bering Sea, Aleutians to Shumagin Islands, Alaska. Circum- 
boreal. 
PLICIFUSUS JOHANSENI Dali, 1919. 
Sci. Res. Canadian Arct. Exp., vol. 8, p. 21 A, pi. 3. 
Point Barrow to Icy Cape, Arctic Ocean. 
? PLICIFUSUS VERKRUZENI Kobelt, 1876. 
Jahrb. Mai. Ges., 1876, p. 70, pi. 2, fig. 1. 
Arctic Ocean to Bering Strait. Circumboreal. 
Subgenus Retifusus Dali, 1916. 
RETIFUSUS VIRENS Dali, 1877. 
Proc. Cal. Acad. Sci., vol. 7, p. 6 ; Sci. Res. Expl. Alaska, pi. 2, fig. 3, 1879. 
Bering Sea to Middleton Island, Alaska. Japan? 
RETIFUSUS INCISUS Dali, 1919. 
Proc. U. S. Nat. Mus., vol. 56, p. 314. 
Arctic Ocean ; Bering Sea ; east to the Shumagin Islands, 38 to 54 fathoms. 
RETIFUSUS OCEANODROMAE Dali, 1919. 
Proc. U. S. Nat. Mus., vol. 56, p. 314. 
Petrel Bank, Bering Sea ; the Aleutians eastward to the Shumagin Islands. 
Section MICROFUSTJS Dali, 1916. 
RETIFUSUS BRUNNEUS Dall, 1877. 
Proc. Cal. Acad. Sci., vol. 7, p. 6 ; Sci. Res. Expl. Alaska, pi. 2, fig. 4, 1879. 
Port Clarence, Bering Strait, to Nunivak and the Pribilof Islands. 
Section LATIFUSTJS Dall, 1916. 
RETIFUSUS GRISEUS Dall, 1889. 
Proc. U. S. Nat. Mus., vol. 12, p. 322, pi. 5, fig. 6. 
Bering Sea (27 fathoms) to San Diego, California (636 fathoms). 
Section HELICOFUSUS Dall, 1916. 
PLICIFUSUS LATICORDATUS Dall, 1907. 
Smithsonian Misc. Coll., vol. 50, p. 161. 
Bering Sea (33 to 76 fathoms) south to Fuca Strait (559 fathoms). 
Genus COLUS Bolten, 1798. 
Subgenus Aulacofusus Dall, 1918. 
% 
AULACOFUSUS SPITSBERGENSIS Reeve, 1855. 
Last of the Arctic Voy., p. 395, pi. 32, fig. 6. 
Circumboreal. Arctic Ocean south to Northern Japan and Fuca Strait, 
12 to 142 fathoms. 
AULACOFUSUS PERISCELIDUS Dall, 1891. 
Proc. U. S. Nat. Mus., vol. 14, p. 187 ; vol. 17, pi. 27, fig. 6, 1894. 
Commander and Aleutian Islands eastward to Sannakh Islands, Alaska. 
167980— 21— Bull. 112 7 
