48 N. ODHNER, NORTHERN AND ARCTIC INVERTEBRATES. VI. PROSOBRANCHIA. 2 SEMIPROBOSCIDIFERA. 



13.4; br. IO.2; h. 6; col. 2.6, $; D:o, 20 fms, rocks (Goés), 1 sp., 1. sli. 11. 5. — Koster, 

 iiiside tlie Islands, 5 — 15 fms (Ljungman 1865), 2 sps, max. 1. sh. 11; br. 8; h. 5.3; col. 

 2.5; spire elevated, whorls 3, ef; D:o, Lindö, 30 fms (Olsson 1869), 1 sp., 1. sh. 5.2; br. 4; 

 h. 2.5; col. br. 1.7, ?; D:o, Andsöholmar, 10 — 30 fms (Olsson 'Vj 1869) 2 sps, max. 1. 

 an. 12; Nordkoster, 90 fms (Loven & Torell), I sh., 1. 5.2; br. 4; h. 2; col. 1; wh. 2. 



Norway withont definite locality (Diiben), 8 sps, max. 1. sh. 17.5; br. 5; h. 3.c; 

 col. br. 1.8; wh. 2 V2, ? (type of Lovén's L. perspicua); an other sh., 1. 7; br. 5.2; h. 3.i; 

 col. 1.6; w^h. 2 V4 (Fig. 3, det. by Loven as L. tentaculata Mont. ). — Finmark (Loven 

 1837), 1 sp., 1. sh. 12.3; br. 9.3; h. 5.5; col. 2.5; wh. 3 (Fig. 5, Lovén's original). —Gröt- 

 sund, 70 fms, clay, together with ascidiae (Goés & Malmgren okt. 1861), 1 sp., 1. sh. 9.5; 

 br. 7; h. 4.5; col. 2, }. 



Limits of Formål Variation, 50 sps measured: 



i. of Shell . . 

 hr. » » . . 

 h. » » . . 

 br. of colnmella 



6—7 

 4—5.4 

 2.4—3.4 

 0.9—1.7 



8—9 

 5.4—7 

 3 2— 4. T) 

 1.3—2.3 



10—11 



12—13 



14—15 



16—17 



max. 18 (Skär) 



5.8—8 5 



8.3—10 



9.8—11.2 



11.2—12.5 



12.2 



3.9—5.5 



4.7—6.7 



5.8 — 7.5 



6.8—8.3 



7.5 



1.8—2.8 



2.3—3.1 



2.6-3.7 



3.1—4.3 



4 



No sexual dimorphism such as Jeffreys (1867) mentions, exists in L. perspicua. 

 There is no rule that the depressed specimens should be males and the more inflated 

 ones females; the proportions vary in both sexes, as is evident from the figures and 

 the statements of the dimensions given above. 



General Distribution:^ 



Norway (Loven 1846); Christianiafjord, Dröbak, 50—60 fms (M. Särs 1870, G. 

 O. Särs 1878). — Bohuslän (incl. »L. tentaculata Mont.»): Väderöarna, 10 fms; Flathol- 

 men (Loven 1846; Malm 1863; Théel 1907). — N. E. of Anholt, about 25 fms, 1 sp. (Pe- 

 tersen 1888, determination somewhat uncertain). — Dogger Bank, var. lata (Hargreaves 

 1910). — Great Britain from low-water mark to 87 fms (Jeffreys 1867); Ireland, around 

 the coast (Nichols 1900). — Faroe Islands (Mörch 1868). — France, less common, down 

 to 180 m (Locard 1892, 1899); N. Bay of Biscay, 87 fms (Jeffreys 1880; Reynell 1909). 

 — S. of Portugal, 364 fms; Tunis (Jeffreys 1885; Nobre 1905). — Madeira? (Mc Andrew 

 1857). — Azores, 1287 m, var. lata (Dautzenberg 1889). — Mediterranean to Aegean, 

 down to 35 fms (Carus 1890). — Cape Verde, var. duhia (Bergh 1887). — Gulf of Aden, 

 var. ceryle (Vayssiére 1912). — Ceylon, var. ceryle (Bergh 1899). — Philippines, var. 

 lära (Bergh 1899). — Japan (Dunker 1885). 



Bergh (1886) considers the N. Atlantic form (= L. producta Leach) to be separate 

 from the mediterranean L. perspicua (Linné), but he admits the possibility of their 

 identity. Forbes & Hanley (1853), Jeffreys (1867) and other conchologists (e. g. 

 Locard 1899) regard them as identical. 



^ The Lainellaria iierspicua of Goukl & Binney, from Massachusetts, fish stoinaclis, is Marseniua glabra 

 CouTHOUY 1839 (^ M. micromphala Bergh 1853), which confer. 



