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



(Petersen 1888). — Faroes (Mörch 1868). — N. of Scotland, W. of Faroe Isles, 

 251 — 539 fms (Jeffreys 1882). - British Islands (Jeffreys 1865). — Dogger Bank 

 (Hargreaves 1910). - W. of Ireland, 90—808 fms (Jeffreys 1882). - North Sea coast 

 of Holland— Belgium (Maitland 1897). — France, to 2020 m (Locard 1899; Reynell 

 1909). — Spain, Vigo Bay; S. of Portugal, var. elata (Jeffreys 1882). — Portugal 

 (Nobre 1905). — Mediterranean (Carus 1889). - Canaries? (Mc Andrew 1852). Depths 

 20 fms to 2020 m. Sand, clay, shells, algse. 



Emarginula crassa So were y 1813. 



PI. 2 figs. 46—50; PI. 3 figs. 1—2. 

 Habitat: 



West coast of Sweden: Kattegatt, S. W. of Nidingen, 40 m, clay, 1 sli., 1. 24.5; 

 br. 18; h. 10 ("% 1911). — Bohuslän: Gullmarn, 50—70 fms, clay (Lindahl) 1 sh., 

 1. 12; D:o, many localities, Figs. 46—48, 1 — 2; Flatholmen and Humlesäcken (1909) 

 a few sps; N. point of Flatholmen ("/t 1908) 1 sp., 1. 35; br. 27 ; h. 17; Äkarberget, 

 60—70 fms, clay (Theel 1887) 1 sp., 1. 20; D:o, 60 fms (Loven 1852) several sps, 

 max. 1. 36.6; br. 27; h. 17. — Väderöarna, 60 fms, corals, many shs, max. 1. 29.5; 

 br. 22.6; h. 12 and 1. 29.6; br. 22; h. 14; 2 sps, 1. 14; br. 10.6; h. 7. — Köster, 

 Styrsö ('78 1886) many sps, max. 1. 29; br. 22.5; h. 15.6; Sydkoster, 5— 20 fms (Eisen 

 & Stuxberg 1871) 2 shs, 1. 18; 1 mile W. of Köster, 20 fms, rocks (Ljungman 

 1865) 1 sp., 1. 25; E. of Stora Sneholmen, Kosterfjorden, 50—150 m, rocks,, mud 

 (I. Arwidsson "Vs 1901); D:o, 60—120 fms (Aurivillius 1895) many sps, max. I. 37; 

 br. 29; h. 17. 



Norway: Christianiafjorden (Asbjörnsen) 2 shs, max. 1. 19; br. 13.5; h. 5.5. — 

 Dröbakegrund, 5—8 fms, corals, many shs, max. 1. 17. — Hardanger (Juel 1878) 1 

 sp., 1. 11. — Bergen (Düben & Koren) 1 sh., 1. 23.5, Fig. 50. — Grötsund, Finmark, 

 100 fms (1861) 2 shs, max. 1. 18.i; br. 13.6; h. 8.2, Fig. 48; and 1. 16.7; br. 12; h. 

 7.5, Fig. 49. 



? Spitzbergen: Norwegian Islands, 18 — 25 fms, hard bottom (Sp. Exp. ^^js 1872) 

 1 sh. (of a fresh appearance) 1. 14.8; br. 11; h. 6. Locality probable confused. 



Limits of formal variation : 



50 sps I. 



18—20 



22 



-24 



26—28 



30—32 



34- 



-36 



max. 37 (Kosterfjorden) 



measured br. 



12.5 — 15,7 



16 



-19 



19—23 



21.5—25.5 



24.5- 



-28 



29 



h. 



5.5 — 10 



7 



-12.5 



9.5—14.5 



11—18.4 



11.5- 



-20 



17 



apex ' 



3—6.8 



4.5 



-8 



5—10.2 



6.5—14 



11- 



-16 



13 



Two extreme formal varieties of Emarginula crassa are common, one depressed 

 and one elevated form, connected by intermediate stages (cfr PI. 2 and 3). 



^ Perpemlieulaiiy from posterior margin. 



