SYSTEMATICAL SURVEY 
OF THE NORWEGIAN SOLENOGASTRES. 
I. No ventral furrow; a pair of bipectinate cloacal gills. Mouth 
surrounded with a shield; atrium without cirri; radula present. 
Spicula squamate, tapering, spear-head-shaped, _ half-raised 
(Chaetodermauna ee Fam. Chaetodermatidae 
Radula with one large median tooth; body elongated 
Chaetoderma Lovén 1844 
Length at most 40-50 times the breadth; dorsal sensory 
organ covered with ordinary spicules ...... 
Ch. nitidulum Lovén 1844 (1) 
II. Ventral furrow present; gills, when present, developed as 
folds (or cirri), not bipectinate. Mouth without shield; atrium 
with cirri (Neomeniina). 
A. Body covered with a spicula-bearing cuticula. 
1. Cloacal øills “presents FR Fam. Neomeniidae 
$ Coelomoducts united to an unpaired terminal sac (,,pre- 
cloacal organ“). 
a. Spicula chiefly open, channel-shaped; hypodermis with 
broad cylindric papillae; no radula; gills a circlet of 
distinct radiating folds; numerous ventral folds; body 
semilunarly curved........ Neomenia Tutvpera 1875 
+ Back keeled; channel-shaped dorsal spicula to a 
great extent with arrow-head-shaped apices, dis- 
tinctly marked off from the shafts. L. to 30 mm 
N. carinata Turisere 1875 
(1) Ch. productum WiréN 1892 is more elongated, has its dorsal sensory 
organ surrounded with shorter spicula and occurs in the Kara and Marmara 
Seas (cf. THIELE 1913) as well as in Spitzbergen, Ice Fjord (Ch. nitidulum 
ODHNER 1916). 
