The adult organisation of Paragordius varius. 403 
lined by cells which have the character of those of the most anterior 
region of the cloaca, and may be termed the posterior intestine. 
In the male the intestine (Int Fig. 83, Pl. 42; Figs. 84, 88, 90, 
Pl. 43) has much the same structural relations as in the female. 
Posteriorly (Fig. 81, Pl. 42) it joins with the laterally placed vasa 
deferentia (Vas) at the anterior end of the cloaca (Cl). 
The cloaca will be described with the genital organs. 
Literature on the intestine. VEJpovskŸ (1886) described 
this organ as consisting of the mouth, the mouth cavity and pharynx, 
the intestine and its aperture; the mouth in Gordius tolosanus is 
closed by a chitinous plate; in G. preslii there is frequently no closure 
of the mouth. Besides the epithelial lining of the intestine he di- 
stinguished an outer “Cuticularschicht, die stellenweise höckerartige 
Verdickungen bildet”. VırLor (1874) states that there is neither mouth 
nor oesophagus in the adult stage; the intestine (1887) consists of a 
“conjunctive” envelope, a fibrous layer, and an endothelium, and its 
diameter is very much shrunken in the adult stage. CAMERANO (1897b) 
states that the mouth opening is generally atrophied in the adult. 
von Linsrow (1889) finds that the mouth is atrophied in the adult 
stage of Gordius tolosanus. 
VI. The Nervous System. 
The central nervous system consists of the ventral unpaired nerve 
cord, with the cephalic ganglion as its anterior enlargement and the 
caudal or cloacal ganglion as its posterior enlargement; at least the 
anterior portion of the caudal nerves in the male must-also be regarded 
as a direct continuation of the nerve cord, and hence as belonging 
to the central nervous system. To the peripheral nervous system 
belong the neural lamella; the endings in the hypodermis of the fibres 
of nerve cells situated in the central nervous system; the hypodermal 
longitudinal nerve; sensory cells placed in the hypodermis which send 
their fibres towards the central nervous system; non-sensory nerve 
cells placed in the hypodermis; and the nerves (nerve fibre bundles) 
which innervate the cloaca in the female, and the vasa deferentia in 
the male. The following description is based upon the female, unless 
there is a statement to the contrary. 
A. The ventral Nerve Cord. 
This lies (N. C Fig. 14, Pl. 37; Figs. 61, 63, 64, Pl. 40; Figs. 65, 
