The adult organisation of Paragordius varius. 397 
d’abord, une système nerveux périphérique, mais bien un appareil 
aquifére, ‘qui communique avec l’exterieur par les canalicules et les 
pores de la cuticule”. No other writer has confirmed either of these 
views, though JAMMES (1894) agrees with VILLoT in interpreting the 
hypodermis as a nervous layer. MICHEL (1888, 1889) demonstrates 
cell boundaries in the hypodermis, which, hovewer, were already known 
at the time of his writing. CAMERANO (1897b and previous papers) 
described the hypodermis, under the name “strato epidermico”, as a 
layer “con cellule a grossi nuclei e con margini sinuosi”. ROHDE 
(1892) terms the hypodermis “Subcuticula”, as do many writers on 
Nematoda, and defines it as a “kôrnig-fibrilläre” protoplasmic mass with 
nuclei. None of these investigators have demonstrated in the hypo- 
dermis sense cells, or nerve fibres, or nerve cells. 
IV. Muscular System. 
A. In the Female. 
The musculature consists of longitudinally directed cells only, 
and forms a sheath (Figs. 2, 3, 14, Pl. 37; Figs. 61, 63, 64, Pl. 40; 
Figs. 65, 66, 68, 70—75, Pl. 41) just below the hypodermis (Hyp), 
absent only in the most anterior region and at the ends of the tail 
lobes. Cross sections show that it is a layer interrupted only in the 
mid-ventral line, where it is interrupted by the neural lamella that 
connects the nerve cord with the hypodermis; at that point the muscle 
cells are deflected upwards on either side of the neural lamella, which 
deflection has been produced by the nerve cord separating from the 
hypodermis and breaking through the musculature. In the mid-dorsal 
line of the greater region of the trunk the muscle elements are not 
arranged in as close a grouping as elsewhere, but still show no inter- 
ruption. Anteriorly the muscle sheath extends forwards to about the 
plane of the ventral commissure of the brain (Muse Figs. 2, 3, 7, 
Pl. 37); and at this point only the attenuated ends of the muscle 
cells are to be seen, and their number is comparatively small. More 
posteriorly, throughout almost the whole trunk. region, the muscle 
cells are closely grouped together, most closely on the lateral aspects 
of the body wall, so as to be greatly flattened by close apposition 
(Fig. 37, Pl. 39). In the tail lobes the musculature is found only on 
the outer surface of the lobes (Figs. 71, 73, Pl. 41), which is clearly 
understandable, since these lobes may be regarded as simply due to 
a splitting .of the posterior end of the trunk. The muscle cells are 
