74 N. ODHNER, NORTHERN AND ARCTIC INVERTEBRATES. VI. PROSOBRANCHIA. 2 SEMIPROBOSCIDIPERA. 



Nova Zembla: Beluscha Bay, Matotschkin Shar, 30 — 50 fms, sand (N. Zemlja 

 Exp. 'V7 1876), 1 sp., 1. an. about 19, sh. 14. 



East Greenland (Hägg 1905, O. groenlandica), max. 1. an. 37, sh. 27, Mackenzie 

 Bay, N. of Franz-Joseph Fiord, 3 — 10 m, mud, sand, Laminariae (Zool. Polar Exp. 

 % 1900), Pl. 1, Figs 17, 23, Pl. 5, Figs. 3, 5, 33. 



West Greenland: Fiskernses, 100 fms, clay (Amondsen 7? 1866), 1 sp., 1. an. 70, 

 sh. 52, determined by Loven as O. palliata n. sp., referred by Posselt & Jensen 1899 

 to O. groenlandica Bergh. — 72° 8' N. 74° 20' W., 30—80 m, härd mud (E. Nilsson % 

 1894), 1 sp., 1. an. 7.5. — Godthaab, 70 fms, clay (Torell), 1 sp., 1. an. 12; sh. 10. 



Tariatioii: 



The osphradium is usually of a whitish colour, as in the typical form, according 

 to Bergh 1887, but this character is not perfectly constant. In most of the specimens 

 from E. Greenland (cfr Hägg 1905), as well as in the specimen from 72° 8' N., the os- 

 phradium has a blackish periphery, and the dark colouration may be spread all över its 

 upper (basal) surface, though not in such intensity as in O. groenlandica. 



The radula has generally denticulated inner uncini, as in the typical form. Only 

 a few exceptions to this rule (with smooth uncini) ha ve been met witli in the material 

 here dealt with: the E. Greenland specimens, the sp. from 72° 8' N., and one sp. from 

 Spitzbergen, Waygat Islands (with uncoloured osphradium). 



In these aberrant forms the posterior end of the foot as well as the penis are of a 

 typical shape, these characteristics thus being of a decisive import for the determination. 



General Distribution : * 



Norway: Hammerfest — Vadsö, 30 — 50 fms (1. 16, sh.; G. O. Särs 1878); Hammer- 

 fest, Tromsö (Bergh 1887); Skatören, Tromsösund, 30 fms, clay with shells (Schneider 

 1895); Kvsenangen, 30^40 fms (Aurivillius 1886); E. Finmark (Norman 1902). — Mur- 

 man coast. Kära Sea (Herzenstein 1893). — Kära Sea, 46 fms (Collin 1887; Bergh 1887). 

 — East Spitzbergen (Krause 1892); Stor Fiord, 102 m, 1 sp., 1. about 37 mm (Knipo- 

 witsch 1902). — ? E. of Iceland, 64° 53' N. 10° W., 600 m (Friele 1902).' — Egedesminde 

 (Bergh 1887). 



Onchidiopsis groenlandica Bergh 1853. 



Pl. 2, Figs. 19, 25; Pl. 5, Figs. 1, 6. 

 Habitat: 



Spitzbergen: South Cape, 2 fms, algae {-'/j 1872), 1 sp., 1. an. 40, sh. 36 (Pl. 5, 

 Fig. 1, 6). — Horn Sound Island (V,, 1861), 1 sp., 1. an. 31,; sh. 27. — Ice Fiord, Dickson 



' The statements are somewliat uncertain, as it is doubtful whetlier in all cases it is the typical form 

 (fixed by Bergh) that is meant by the authors. Friele & Grieg 1901 include in the present species also O. 

 groenlandica Bergh; one of their specimens, examined by me, was O. groenlandica (cfr Bergh 1887). 



