36 



NILS ODHNER, NORTHERN AND ARCTIC INVERTEBRATES. III. Ol'ISTHOBRANCHIA ETC. 



A. Gills oblong; rhinophores cylindrical, with a longitudinal furrow; radula 0.1.0 

 with 40 — 50 teeth Herma?a Loven. 



B. Gills inflated; rhinophores simple, conical; radula 0.1.0 with 15—21 teeth 



Stiliger Ehrenberg. 



II. Body broad, ovate; no rhinophores nor oral tentacles; papillae in transverse rows on 

 the sides of the back; anus dorsal, placed far back; radula 0.1.0 with 16 — 17 teeth 



Alderia Allman. 



Henna^a Loven 1844. 



I. The branchia? broadly oblong, of differing size. The tips of the rhinophores with 

 a short lobe behind (the apex seems to be forked). Body white with red lines, 

 branchia? with red liver-processes. L. 24 mm. H. bifida (Montagu 1815). 



PI. Ill fig. 29. 



II. The branchiae nearly linear, set in 8 rows. The tips of the rhinophores rounded. 

 Colour brownish green with branched greenish lines; branchia? of the same colour. 

 L. 8—10 mm. H. dendritica (Alder & Hancock 1843) 



= venosa Loven 1844. 



PI. Ill fig. 28. 



Stiliger Ehrenberg 1831. 



Papilla? 16 — 20 on each side, the largest innermost; rhinophores pointed, 

 as long as the anterior papillae; foot with projecting angles, narrowly produced be- 

 hind. Colour gray or blackish, marbled with white; tail reddish white; rhinophores 

 grayish; at each side of the neck a dark line and inside them a light one with the 

 eyes on it. Close by the anus a dark line curved backwards (due to the translucent 

 salivary gland). L. 7 mm. 



S. Maria? (Meyer & Möbius 1865) =? Tergipes bullifer Loven 1846. 1 



Alderia Allman 1844. 



Head short with obtuse side-lobes. Processes in 6 — 7 rows, cylindrical with 

 rounded apex, longer towards the hinder end of the body. Foot very broad with 

 the margins deflected upwards. Colour yellowish or greenish, marbled with white. 

 L. 10 mm. A. modesta (Loven 1844). 



PI. II fig. 25. 



Fam. Elysiidae. 



KJysia Risso 1812. 

 Radula 0.1.0 with 40 — 50 teeth; anus dorsal. 



Colour brownish or blackish to olive-green with shining red, blue and green 



1 Judging from specimens determined by Luven and from a picture of an undefined Nudibranch, which 

 seems to correspond to Loven's diagnosis of Tergipes bullifer; this species may be identical with S. Maria«. 



