: 36 NILS ODHNER, NORTHERN AND ARCTIC INVERTEBRATES. V. PROSOBRANCHIA. 1 DIOTOCARDIA. 
80—100 fms, 3 shs, max. 1. 5.5; br. 4; h. 2.3; apex 0.7, grayish white, coarsely sculp- 
tured; var. albula (Fig. 23). — Norway, without definite locality, many shs, max. 1. 
9.3 (Duben). 
Limits of formal variation: 
= | FEB 8—9 9—10 |max. 9.5 (Väderöarna) 9.8 Christia- 
Scandinavia; 1.| 3—4 | 4-5 | 5—6 | 6 | 
50 sps Ds (UN [RAN | Nb | HAN) BA | SA) Be—B5) + ökord 
[neasured NI IA RA | 2 | 2.4—3.3 | 2.4—(3.3) 27 23 
apex |(0.7)—1 | 0.6—1.2 | 0.7—1.4 | 0.8—1.7 | 1.8—2 1.5—2.4 | 1.9—(2.7) 21 2 
Numerals in a parenthesis are calculated. 
Structural variation: radiating riblets are always present, though more or less 
conspicuous, especially prominent in specimens from Grötsund, Norway. — Colour 
variation: from light yellowish to reddish or brownish ; specimens from Grötsund differ 
from the typ by their uniform white colour (var. albula Jeffreys, Fig. 23). — Speci- 
mens of unusual breadth are named by Jeffreys as var. expansa (Figs. 18, 19). 
General Distribution: 
Norway: Vadsö, southwards, 10—180 fms (Aurivillius 1888; 1. 9, G. O. Sars 
1878; Norman 1902; Krause 1887); Varangerfjord, 20—124 m (De Guerne 1886); 
western coast (Friele 1874; Metzger 1875, 0—35 fms; Nordgaard 1907). — Christiania- 
fjord, 10—140 fms (Asbjörnsen 1854; Jeffreys 1870). — Bohuslän, 20--70 fms 
(Malm 1855); Göteborg Skärgård, 23 fms (Malm 1858); Kullen (Lilljeborg 1855). — 
Hellebek, Denmark, 16 fms (Mörch 1871); Kattegatt (Petersen 1888). — North Sea 
and Fair Isle Bank, to 286 m (Simpson 1910+ var. albula and expansa). — N. of 
Hebrides, 170-—189 fms (Jeffreys 1869); Western coasts of British Isles, 10—1900 fms 
(Jeffreys 1865). — France, very rare (Locard 1892, 1899). — Azores, 1,000 fms 
(Watson 1886). Depths to 1,000 fms. Rocks, sand, clay. 
Scissurella crispata FLEMING 1832 
(incl. var. angulata LovÉn and var. aspera PHILIPPI). 
Pl. 2 figs. 26—27. 
Habitat: 
Bohuslän: Väderöarna, 60 fms, corals (Lovén) 2 shs, max. h. 1.s; aperture 1.3; 
br. 2.5; wh. 3/4; Svinesund, 30-70 fms, mud with stones (Lindahl) 1 sh.; h. 3.5: 
aperture 2.4; br. 4.2, wh. 4'/2; var. angulata. — Norway; Dröbak, 60 fms, clay, sev- 
eral shs (Lovén 1850), max. h. 4.2; aperture 2.7; br. 5; wh. 4”/1 (Fig. 27); Grip 
(Lilljeborg) 1 fragm.; var. angulata; Bergen, 70 fms, sand (Lilljeborg) type and var. 
aspera; D:o, (M. Sars) 2 shs, h. 2.3; aperture 1.3; br. 2.7; wh. 4; Fig. 25, var. aspera; 
Finmark (Lovén) 2 shs, max. h. 1.s; aperture 1.3; br. 2.4 var. angulata (original). — 
