30 N. ODHNER, 2SURTHERN AND ARCTIC INVERTEBRATES. VI. PROSOBRANCHIA. 2 SEMIPROBOSCIDIFERA. 



Lunatia nana (Möller 1842). 



Pl. 4, Figs. 22—25. 



Habitat: 



Norway: Vardö, Finmark, in the siirface (Sandebcrg -'Ve 1877), 1 sp., h. 4.4; ap. h. 

 3.5; br. 4.i; ap. br. 2.j; lunb. 2.?; sut. 1; wh. 3 + (Fig. 24). — Beeren Island, 20 fms, "gra- 

 vel (-y? 1868), 1 sh., h. 5.7; ap. h. 4.8; br. 5; ap. br. 3; umb. 2; sut. I.3; wh. 3 'A; shell 

 bored (Fig. 24). — Spitzbergen, without definite locality (Torell), 3 sps, max. h. 6.8; ap, h. 

 6; br. 6.3; ap. br. 3.7; umb. 2.3; sut. l.s; wh. 37. (Fig. 22). — Iceland: Raufarhofn (Odhner 

 1910), 25 — 40 fms (Torell), 7 sps, max. h. 4.7; ap. h.* 4.2; br. 4.8; ap. br. 2.3; umb. I.9; 

 sut 0.7; wh. 3 Va (Fig. 23). — N. W. Atlantic, 52° 5' N. 52° 19' W., 161 fms, stones, clay (Inge- 

 gerd & Gladan Exp. "/« 1871), 2 shs, max. h. 6; ap. h. 5.2; br. 5.7; ap. br. 3; umb. 2.2; 

 sut 1.3; wh. about 3 (placed by Posselt & Jensen 1899 among Natica clausa). — Da- 

 vis Strait, 63° 47'.5 N. 52° 26'.2 W., 35 fms, shells, in the archipelago (Ingegerd & Gladan 

 Exp. Vb 1871), 1 sh., h. 5.7; ap. h. 4.8; br. 5.2; ap. br. 2.8; umb. 2; sut. I.4; wh. 4 Vs (Fig. 

 25; Posselt & .Tensen 1899). — Greenland, without definite locality, 1 sp., h. 5.2; ap. 

 h. 4.7; br. 5,2; ap. br. 3.7; umb. 2.i; sut. 1; wh. about 4 (Möller's original, Fig. 25). 



Variation of shell and radnia. 



The spire is depressed in Möllee.'s original specimen (Fig. 25) and in those from 

 Iceland, elevated in the other shells. The figure given by G. O. Särs 1878 (Tab. 21, 

 Fig. 16) is an intermediate one, so that these forms may be considered extreme varieties 

 of the samespecies. Thecolour of the first-named shell (Möller's original) is light yellow- 

 ish brown, of the others white. Tryon (1886) iniites L. nana with Natica immaculata 

 Totten; b ut the two forms are specifically distinct, as the last-named has its »inner 

 lip coated with ivory-white callus, iipt modifjång the umbilicus», which is »rounded 

 and deep» (Gould & Binney 1870). — The radula of a specimen from Spitzbergen (h. 

 5.2) shows a broader median tooth than in G. O. Särs' Fig. 14, Tab. V (1878), and the 

 other teeth too are somewhat more produced in a transversal direction. 



General Distribntion: 



Norway: Vadsö, 50—60 fms (h. 5; G. O. Särs 1878); Vardö, in tlie stomach of Ga- 

 dus seglefinus (Sparre Schneider 1894; Friele & Grieg 1901); E. Finmark (Norman 1902). 



— Murman coast, White Sea (Herzenstein 1893). — Kolguev Island, 60 fms (Mel vill & 

 Stånden 1900). — Spitzbergen, The Norwegian Islands, 15 fms (Friele & Grieg 1901). 



— Iceland (Mörch 1869? as Natica boreahs Gray; Odhner 1910). — West Greenland 

 (Posselt & Jensen 1899, cfr above). — Le Have Bank, Nova Scotia, 45 fms; Gaspé Bay, 

 Gulf of St. Lawrence (Whiteaves 1901). — Nova Scotia to Cape Hatteras, 27 — 28 (dead 

 to 430) fms (Verrill 1882—85). — Gulf of Gascony, 1710 m; W. of Africa, 175—640 m 

 (Locard 1897, 1899). — Aleutian Islands (Jeffreys 1885). Depths to 1710 m. 



