Norwegian Solenogastres 19 
copulatory organ (fig. 2, c.o.) consisting of a muscular sheath 
fixed anteriorly by means of muscle fibres at the sides of the body 
(fig.14, m) laterally to the coelomoducts; the sheaths each contain 
two spicula one being straight and the other somewhat contorted 
and c-shaped. Outside the openings of the copulatory organs 
there appear a pair of vesiculae or sac-formed glands (fig. 2, v.) 
constituted by an invagination in the wall of the cloacal cavity. 
The nervous system offers nothing of special interest. A 
dorsal sensory organ exists, but is observable only in sections. 
It is situated at the rear end of the body, opposite to the cloa- 
cal opening. In the cuticula there is a small round hole and 
from the bottom of this there rises a small swell consisting of 
aggregated elongate cells. The latter are supported by a pro- 
jection of the subjacent parenchyma. The material was not 
adapted for closer analysis. Pedal and lateral nerve cords termi- 
nate without being combined: the former beneath the unpaired 
part of the shell gland where the nerve cords form a pair of gang- 
lia, the latter by means of a supra-rectal commissure. 
Round the coelomoducts the ventral blood vessel widens to a 
sinus between the former and the wall of the body. Along the large 
inner sides of the cloaca the blood is carried away to the gills 
where it is arterialized, and then passes through the parenchyma 
on the upper side of the cloaca into the two auricles of the 
heart. From the ventricle it is pressed forward through the 
dorsal blood vessel to the head region where the latter opens 
into a lacunar system in communication with the ventral sinus. 
Drepanomenia incrustata KOREN & DANIELSSEN 1877 (Solenopus). 
(Figs. 17—24). 
Hasvik, Finmarken, 200—300 ims, 1 sp., 1. about 20 mm 
(in a contracted state; prototype; B). 
Diagnosis of the species: Body relatively short with both 
ends rounded, circular in section without dorsal keel, covered 
with a thick cuticula containing radiating needle-shaped hollow 
spicula (1. about 0.25 mm). Ventral furrow with 5 folds exten- 
ding from the ciliated crypt to the cloacal cavity. The latter 
with a circlet of branchial folds. Pharynx with thick folded 
walls and with a thin sub-oesophageal pocket. Length of animal 
