44 NILS ODHNER, NORTHERN AND ARCTIC INVERTEBRATES. V. PROSOBRANCHIA. 1 DIOTOCARDIA. 



Gunhild Exp. ^"A 1878) 4 sps, max. h. 8.1 ; ap. 4; d. 9.3; whorls 6. — Göteborg 

 Skärgärd: Svartskär— Vinga, 26 m (Lagerberg "/7 1906) 1 sp. ; D:o, Tistlarne, 26 m, 

 and Buskär, 26—53 m (Mus. G.). — Bohuslän, numerous shs (1838) max. h. 13; 

 ap. 7; d. 15.2; whorls 6 + (Figs. 5 and 7); Marstrand, N. Nordholmen — Langdals- 

 udden, 20—38 m (Lagerberg ^''/t 1906) 1 sp.; D:o, N. Ästol— Dyrön, 18—36 m 

 (Lagerberg ^V? 1906) 2 sps; Gullmarn, off Längegap, 30 m, clay and dead 

 Zostera (-'V7 1907), 1 sp., overgrown by algae; h. 12; ap. 4.6; d. 11.2; Kristineberg, 

 many localities (Theel 1907); Skatholmen, 5 — 6 m, stones, gravel, algae (^% 1903), 

 many sps, max. h. 9.7; ap. 4.2; d. 10; Delsboudd, 18 — 35 fms and Aisbäck, 70 fms 

 (Mus. G.). — Väderöarna, numerous sps, max. h. 12.8; ap. 5.6; d. 12.5; D:o, 60 fms, 

 corals, many shs, max. h. 13.7; ap. 6.4; d. 13.5; wh. 7; St. Väderö, 10 — 90 fms (Olsson 

 1869), many sps. — Lindö (Olsson 1869) 1 sh. — Dyngö, 15 fms, clay, 1 sp., 

 h. 10. — Ramsö, 10 — 25 fms, clay mixed with sand (Eisen & Stuxberg 1871) 1 sh. 



— Sydkoster, 5 — 20 fms, rocks (E. & S.) many sps, max. h. 12.8; W. of Sydkoster, 

 2 — 6 fms (Ljungman ^^/t 1865) many sps, max. h. 12; Nordkoster, inside the islands, 

 2 — 6 fms, clay, sand (L. 1865) many shs; Kosterfjorden, 18 fms, clay (L. ^^ji 

 1865) many sps, max. h. 15.4; ap. 6.6; d. 14; wh. 7; D:o, 5—15 fms, rocks (L. 

 1865) many shs. — Kilsund, Skagerrack, 40 fms, shells (Gunhild Exp. ^ji 1877) 1 sh., 

 d. 9. — Strömstadsf järden, 8 — 15 fms (Hanson % 1881) 1 sp. 



Norway: Christianiaf jorden (Asbjörnsen) many sps, max. h. 13; ap. 5.6; d. 12.8-, 

 transition form to G. tumida: h. 11; ap. 5; d. 13. — Dröbak. 5 — 8 fms, corals, 7 

 sps, max. h. 10.8 ; ap. 5.i; d. ll.i; wh. 6. — Hitterö, 20—30 fms (Oberg 1869) a 

 few sps, max. h. 6.3; ap. 3.6; d. 9; wh. 5V2. — Stavanger (v. Friesen) many shs, 

 max. h. 12; ap. 6; d. 13.2; wh. 6. — Flekkefjord, 15—20 fms (Oberg 1869) 3 sps. 



— Haugesund, 32 fms (Bovallius) many sps, max. h. 12.5; d. 14.5; wh. 6. — Far- 

 sund, many sps, max. h. 8.7 (Mus. U.). — Gravenfjord, 150 fms, shells (Bovallius 

 1880) 1 sp., h. 5.5, — Bergen, many sps, max. h. 13.6; ap. 6.2; d. 15. 1; wh. 6 Va? 

 Fig. 4. — Body bet, 2 shs, max. d. 5.6. — Finmark: Ulfsfjord, 2 shs, max. h. 9; 

 d. 11; wh. 6 — Karlsösund, 15 fms, stones, corals (1861) 5 shs, max, h. 11.7; 

 d. 13.7; wh. 7, Fig. 4. — Tromsö (Lilljeborg 1848) 7 sps, max. h. 15.2; d. 14.7 (Mus. 

 U.). — Finmark (Loven) many shs, max. h. 19.4; ap. 8.8; d. 19, Fig. 6. 



Shetland: Baltasound on stones at the shore (Hammarsten 1909) many sps, 

 max. h. 15; ap. 7.6; d. 17.4; wh. 6 ^jz; shells unusually solid. 



Limits of formal variation: 



Scandinavia; Height of shell 



4—5 



6—7 



8—9 



10—11 



12-13 



14—15 



18—19 



max. 19.4 (Finmark) 



100 sps Height of aperture 



2 3—3.2 



3—4.2 



3.8—5.4 



4.6—5.9 



5—7 



5.7—7.6 



7.5—8.8 



8.8 



measured Diariieter of shell 



5.3 —7.5 



4—10.2 



9.3—12 



10.6—13.6 



11.3—15.2 



13.2—17.6 



17.2—19 



19 



Whorls 



5 



5—5 V2 



6 



6^6 V-' 



6—7 



> 6 1/2 







The variation is considerable as well on the Swedish as on the Norwegian 

 coast; the breadth of variation is similar in both districts. Specimens from Fin- 

 mark, collected by Loven, show the maximal dimensions; such are, however, usually 

 smaller than southern forms of the same number of whorls. 



