Norwegian Solenogastres. 13 
Description of the Anatomy. 
The cuticula (fig. 3) of the present form is of moderate thick- 
ness and contains only two or three layers of tangential spicula 
directed obliquely to the longitudinal axis of the body and 
crossing each other almost at right angles (fig. 7). From the 
thin epidermis (hypodermis) there rise at rather wide intervals 
multicellular papillae with thick stalks and only slightly widened 
ends, resembling those of Neomenia (ci. Wirén 1892). Only the 
sides of the ventral furrow are clothed with radiating spicula. 
Inside the cuticula there follows a thin layer of circular 
muscles and inside it a longitudinal one. The latter, on the 
ventral side, forms two strong muscular strings or flattened fas- 
ciculi at the sides of the ventral furrow, attenuating toward the 
lateral sides of the body. They are covered interiorly by a sheath 
of diagonal muscles, from which a few thin diagonal fibres pene- 
trate the longitudinal fascicles laterally, while stouter ones extend 
towards the upper sides of the body, forming the rather diffused 
septal muscles between the intestinal diverticula. 
In a transverse section through the median part of the body 
the following features of organization are observed (fig. 11): The 
gonads occupy a position dorsally of the intestine and form, due 
to their maturity, a more or less dilated pair of tubes; the intes- 
tine thus to a greater or less degree extends over their sides. 
Between the intestine and the outer body wall there appears a 
large space occupied by lacunae containing blood and lymphatic 
corpuscles. Beneath the intestine a broad ventral blood sinus 
appeared, which did not seem to be separated from the lateral 
lacunae; frequent communication between them and the sinus takes 
place in the lateral angles of the vessel. Inferiorly this sinus is 
limited by the thin diagonal muscle sheath inside the ventral muscle 
fascicles, and its roof is formed by a membrane immediately fixed 
te the wall of the intestine, along its median zone. On both sides 
of the ventral sinus, in the centre of its lateral parts, the foot 
gland appears as an accumulation of strongly cyanophilous cells 
at both sides of the diagonal muscle sheath, here and there con- 
nected with strings of glandular cells which follow its outer side 
to the ventral furrow. Outside the pedal gland, in the angle 
between the longitudinal and diagonal muscles the pedal nerve 
cords are located. The weaker lateral cords are situated higher 
up but below the middle of the body, inside the muscular layers. 
