3 Nils Hj. Odhner. | 
Unfortunately only one specimen of this small, apparently 
very interesting, animal was preserved. For this reason the exa- 
mination of the species has been very incomplete, leaving some 
of the most important points of its organization unascertained. 
As the present specimen contains mature genital products, eggs 
as well as spermatids, there can be no doubt that it is a fully 
developed individual. Even its external shape is aberrant, as the 
foremost seventh of the body is set off, by means of a constric- 
tion, to get the shape of a thorax (fig. 44); in this character, as 
well as in the shape and the gleam of the spicula (fig. 47), and 
in the presence of a thin cuticula and a single epidermis layer 
(fig. 48), it bears a striking resemblance to a Chaetoderma. The 
presence of a ventral furrow and of cloacal gill folds, however, 
proves it to belong to the family Neomeniidae, though there are 
fundamental differences from its known members. A similar in- 
vagination as in Simrothiella though much deeper and lined with 
a smooth, not folded, ciliated epithelium separates the ventral 
furrow from the cloaca. The fold within the furrow is com- 
posed of elongated epithelial cells interspersed with glandular 
cells and fine fibres of connective tissue. 
The epidermis (fig. 48) consists of only one single layer of 
small cubic cells intermixed with larger glandular ones con- 
taining a vacuole and a basal content of grains stained with haema- 
toxylin. These cells certainly correspond to the socalled giant cells 
(,,Riesencellen“ of WirREN) in Chætoderma. On the surface of the 
epidermis the spicula project — their formation was not studied — 
covered on each side by a thin cuticula, which is apparently pro- 
duced by the mass of the small cubic cells. Towards the rear 
end of the body the spieula increase slightly in size. 
Beneath the cuticula there is a thin circular muscle stratum, 
and inside it a layer of obliquely circular fibres crossing each 
other; innermost there follow small isolated longitudinal muscle 
cords. These are most frequent on the lateral and the ventral 
side of body; at each side of the ventral furrow they are most 
crowded, but can be said to form a longitudinal fascicle only in 
the posterior part of body, since it is only here that the layer is 
thicker on the ventral side than elsewhere. From the median line 
radiate thin diagonal fibres which constitute the very feeble septal 
muscles. On both sides of their roots the pedal glands are 
agglomerated, and between their inner sides runs the ventral 
