62 
Form of the female: The anterior and posterior portions of the body are narrower 
than the middle, the decrease in diameter being very gradual; the anterior is 
narrower than the posterior end. The head end is obliquely truncated in such a 
way that the antero-ventral margin projects farther forward than does the antero- 
Pa rsgordius varios. 
Fig. 49. 
Fig. 53. 
Z<rt>e jioe^ 
Fig. 50. 
Fig. 52. 
Enlarged. (After Montgomery, 
(After Montgomery, 1898, 
Fig. 49. — Dorsal view of tail of female. 
1898, fig. 88.) 
Fig. 50. — Cross section of same. Enlarged, 
fig. 80.) 
Fig. 51. — Optical section of the caudal end of a female P. varius, showing 
anatomy; x-y, omitted portion, about 10 times the length of x-z. En- 
larged. (Reduced from Montgomery, 1898, fig, 86.) 
Figs. 52-53. — Transverse section and surface view of cuticle of female. En- 
larged. (After Montgomery, 1898, figs. 9l a-b.) , 
Fig. 54. — Surface view of cuticle of male. Enlarged. (After Montgomery, 
1898, fig. 93.) 
1 
Ns 
dorsal; this truncated plane, which forms the terminal aspect 
of the head, is very nearly flat. , The mouth lies near the 
yentral edge of the truncated plane. The posterior end is 
trilobed, there being one dorso-median and two latero-ventral 
lobes; these lobes have no cuticular spines on their surface, 
and in the great majority of the numerous specimens exam- 
ined are of equal length. Two specimens in the Harvard col- 
lection were exceptions to this equality in length; in one the 
dorsal lobe was slightly longer than the others, in the other 
slightly shorter. But the dorsal lobe is narrower than the others, and further differs 
from the latter in having an elevated median ridge on its ventral surface, so that 
on cross section it appears triradiate. The lateral lobes are crescent-shaped on 
cross section. The cloacal aperture, wholly hidden, by these lobes, lies at their 
Fig. 51. 
