Norwegian Solenogastres. 49 
and thus separated from the cloacal cavity. No gills. Epidermis 
forming all round the body a simple layer of crowded epithelial 
cells, each clothed externally with a thin cuticula marked off from 
that of the adjecent cells by erected margins; body surface thus 
covered with a peculiarly differentiated cuticula composed of micro- 
scopical pieces separated by a mash-work of fine cuticular lists. 
Cirrose area well separated from mouth. Pharynx embolic, with 
thick, glandular lips and without radula. Anterior coecum of inte- 
stine indistinct. Intestinal diverticula broad and spacious, alter- 
nating with very distinct and numerous thin dissepiments, shining 
through and distinctly visible from without. Coelomoducts with 
short proximal legs debouching into the widened distal legs without 
differentiated vesicula seminalis; distal portion unpaired; on each 
side ventrally of the shell gland a copulatory organ in the shape of 
a vesicula containing two spicula. 
Gymnomenia pellucida n. sp. 
(Figs. 75—88.) 
Animal semitransparent, with a feeble iridescent gleam caused 
by the microscopical net-work of the erect cuticular lists of the epi- 
dermis cells. Length 4.5, breadth and height about 0.65 mm. 
Locality: Sunde, Hardangerfjord, together with Chaetoderma, 2 
sps., max.l. 4.5 (G. O. Sars; K.). 
That the present two specimens of this remarkable new form 
of Solenogastres are full-grown individuals is proved by the occur- 
rence of mature genital products of both kinds which could be esta- 
blished both on animals in toto and on sections. Unfortunately the 
scantiness of material in this case, as in that of Wirenia, has pro- 
hibited a thorough investigation, but the details which I was able 
to establish are quite sufficient not only for assigning to this form 
a position among the Solenogastres, but also to create for it a new 
genus forming the type of a distinct family and offering charac- 
teristics seemingly more primitive than in other Solenogastres, and 
thus of importance with regard to the relations and phylogeny of 
these animals. 
The very external shape of Gymnomenia pellucida shows it to 
be different from all other Solenogastres. The body (fig. 75) is, 
in fact, not regularly rounded in section as is usual in this group, 
but has a flattened under side, and the lateral sides are somewhat 
concave. This concavity is very distinctly marked in the posterior 
4 
