24 NILS ODHNÉR, NORTHERN AND ARCTIC INVERTEBRATES. III. OPISTHOBRANCHIA ETC. 



3.1.0.1.3 (Ålder & Hancock 185P) or 5.1.0.1.5 (G. O. Särs 1878), with the 

 laterals denticulated. Colour white or yellow. L. about 30 mm. 



A. pilosa (Muller 1776) = tomentosa (Loven 1846). 



P II figs. 1,3—15. 



Colom' brown or blackish var. fusca (Loven 1846). 



Pl. II tig. 12. 



II. Gills 15, simply pinnate: rhinophorial orifice slightly crenelated; papilise close, 



nearly cylindrical; radnia 3.1.1.1.3, the laterals smooth. Colour whitish or 



dirty yellow. L. about 30 mm. A. sibirica (Aurivillius 1887), 



Adalaria Beegh 1879. 



I. Papillse club-shaped; radala 10. 1 .0. 1 . 10. Body semi-transparent, white or yellow. 



L. 14—25 mm. A. proxima (Ålder & Hancock 1845'') = echinata (Loven 1846). 



IT. Papillae broadly rounded; radula 12.1.1.1.12 (Särs 1878).' Colour yellowish 



white. L. 20 mm. The biggest papillse at the middle and along the sides of the 



back, smaller ones on the margins, interspersed with minute ones all över 



A. Lovéni (Ålder & Hancock 1862) 

 = Doris muricata Muller of Loven 1846. 



LamellidoriN ålder & Hancock 1855. 



I. Radula with lamina media: (1 — 2). 1.1. 1.(1 — 2). 



A. Radula 1.1.1.1.1; gills 20 — 30 ; lam. lat. not denticulated, papillae verruci- 

 form. C'Olour yellowish, marbled with brown on the back. L. 25 mm. 



L. bilamellata (Linné 1766). 

 Gills 16 var. liturata (Möller 1842). 



B. Radula 2.1.1.1.2; lam. lat. minutely serrated (denticles 15—20); gills 11; 

 papillse club-shaped or rounded. 



1. The under side of the pallial margin smooth; papillae uniform in size; co- 

 lour yellowish. L. 10 — 13 mm. L. muricata (Muller 1776). 



2. The underside of the mantle furnished with close -set papillae. Body 

 semi-transparent. L. 10 mm. L. aspera (Ålder & Hancock 1842). 



3. The underside of the pallial margin with a few papillse and with y- 

 shaped lines; body transparent (the intestines showing through). Colour 

 white. L. c. 10 mm. L. diaphana (Ålder & Hancock 1845^). 



II. Radula without lamina media: 1.1.0.1.1. 



A. Laterals of the radula denticulated, uniformly arched and furnished with a 

 strong hook near the apex. 

 1. Gills 9. 



a. Apertures of tlie rhinojjhores lobated ; papilbe nl)tuse. rather sparse. Colour påle yellow witli 

 distinct brown spöts. L. 7 mm. L. sparsa (Aldee & HAXCOcac 1846''). 



b. Apertures of the rhinophores smooth; papillae short, conical, close-set. 

 Colour brown. L. 9 mm. L. pusiUa (Ålder & Hancock 1845^'). 



^ The lam. med. wanting aecordlng to Aldek & Hancock 1862; forraula in Friele it Hansen 187(5: 

 12.0.12. 



