44 Nils Hj. Odhner. 
max. 1. about 14, h. about 0.8 mm (TH. MORTENSEN, July 1911 
and Aug. 1916; C, cf. fig. 67). 
This variety, the colour of which seems to have been light 
grayish red — a trace thereof has remained in the alcoholic spe- 
cimens — differs from the type in the shape of its spicula, which 
have their base abruptly truncated, as well as in their size, which 
is somewhat smaller. In all other respects, the present form agrees 
with the type as described by Pruvot 1891 and THIELE 1894. 
The type attains a length of 30 mm and is found climbing in 
Lafoéa dumosa; its most northern locality is Plymouth (Gar- 
STANG 1896); otherwise it has only been found at Roscoff and 
in the Mediterranean. The spicula of the present form recall 
those of Nematomenia arctica described and reproduced by THIELE 
in 1913, but the anatomy shows considerable discrepancies, in as 
much as the latter has a straight oesophagus and two pairs of 
vesiculae seminales. Though the typical form has been described 
thoroughly by the authors mentioned, I will nevertheless give 
some brief notes on the morphology and the anatomy of the 
variety in order to illustrate the points of agreement and to call 
the attention to certain characteristics hitherto insufficiently 
noticed. | 
The specimens, which were irregularly coiled round the 
branches of Grammaria colonies (fig. 67), had a thread-shaped 
body which was higher than broad and furnished with a distinct 
dorsal keel (figs. 68, 69) formed exclusively by the erect. spicula. 
There were the same kinds of spicula as in the type with the 
above-mentioned difference that the bases were abruptly truncated 
or at most almost inconspicuously concave. The largest scale- 
shaped spicula (fig. 72a) measured 0.25 mm in length and covered 
the sides of the body, being intermingled with narrower ones (d); 
at the sides of the ventral furrow the former were replaced by 
scales of a more lanceolate shape (b, c). 
As to the external shape of the body it should be observed 
that the transverse section shows a concave outline of the lateral 
sides (fig. 74), a feature rather common in the family Lepidome- 
niidae and of importance for understanding the morphology and the 
relations of the Solenogastres (see further below, comparative part). 
It also deserves to be noticed that the ventral furrow, just as in the 
type, is destitute of a differentiated longitudinal fold and that the 
epithelium covering its bottom, as already noticed by THIELE (1894), 
