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, alge. 
Emarginula crassa SowERBY 1813. 
Pl. 2 figs. 46—50; Pl. 3 figs. 1—2. 
Habitat: 
West coast of Sweden: Kattegatt, S. W. of Nidingen, 40 m, clay, 1 sh., 1. 24.5; 
br. 18; h. 10 ("”/s 1911). — Bohuslän: Gullmarn, 50—70 fms, clay (Lindahl) 1 sh., 
I. 12; D:o, many localities, Figs. 46—48, 1—2; Flatholmen and Humlesäcken (1909) 
a few sps; N. point of Flatholmen ("”/7 1908) 1 sp., 1.35; br.27; hh. 17; Skårberget, 
60—70 fms, clay (Théel 1887) 1 sp., 1. 20; D:o, 60 fms (Lovén 1852) several sps, 
max. I; 36.5; br. 27; h. 17. — Väderöarna, 60 fms, corals, many shs, max. 1. 29.5; 
bra 22.530; 12 ramdsolk 29:55 br:22;sh) 143 208ps, Ilarl4; brå 10:65 Koster, 
Styrsö ('”/s 1886) many sps, max. 1. 29; br. 22.5; h. 15.5; Sydkoster, 5—20 fms (Eisen 
& Stuxberg 1871) 2 shs, 1. 18; I mile W. of Koster, 20 fms, rocks (Ljungman + 
1865) 1 sp., 1. 25; E. of Stora Sneholmen, Kosterfjorden, 50—150 m, rocks, mud 
(I. Arwidsson ””/s 1901); D:o, 60-120 fms (Aurivillius 1895) many sps, max. I. 37; 
br 205 
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., I. 11. — Bergen (Diben & Koren) 1 sh., 1. 23.5, Fig. 50. — Grötsund, Finmark, 
100:fms (1861);2-shs; max.-I, 182;, brind3.-6srb3 82 Mig 485srand IlLGNGIPRAL25EN 
1.5, Fig. 49. 
? Spitzbergen: Norwegian Islands, 18—25 fms, hard bottom (Sp. Exp. '”/s 1872) 
1 sh. (of a fresh appearance) 1. 14.8; br. 11; h. 6. Locality probable confused. 
Limits of formal variation: 
50 sps 1 18—20 22—24 26—28 30—32 | 
| | 34—36 | max. 37 (Kosterfjorden) | 
measured br. |12.5—15,7| 16—19 19—23 121.5—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 ARS B—=10:21"6.5=T4 | ENG 13 
Two extreme formal varieties of Emarginula crassa are common, one depressed 
and one elevated form, connected by intermediate stages (cfr Pl. 2 and 3). 
! Perpendicularly from posterior margin. 
