372 
Ascarids in the British Museum 
being slightly narrower than its more lateral fellow. The dorsal hp 
measures 0-24 mm. across at its base, the ventro-lateral lips 0T9 mm. 
Each of the three lips is provided with a simple dentigerous ridge on 
its inner side near the anterior end, the teeth being somewhat irregular 
in size and arrangement. 
The oesophagus is divided, as in A. decipiens and other related 
forms, into an anterior muscular portion, and a posterior portion 
which is opaque and granular in appearance, and possibly glandular 
in function. The latter portion is frequently bent in the form of an S, 
as observed by Stiles and Hassall (1899) in the case of Ascaris typica. 
The ahmentary canal bears no caeca or diverticula of any kind, differing 
markedly in this respect from that of A. decipiens. 
There is a ventral excretory gland, which appears to be precisely 
similar to that of A. decipiens, and opens, in the same way, by a small 
pore situated between the ventro-lateral hps (PI. XV, fig. 2, Ex. P.). 
The tail of the male (PI. XVII, fig. 1) has normally a strong ventral 
flexure. It is bordered laterally, at the tip only, by a slight cuticular 
expansion. The sides of the body do not show the marked expansion in 
front of the tail, which was observed in A. decipiens. There are eleven 
postanal papillae, viz. five pairs, and an unpaired papilla near the 
extreme tip of the tail. In front of the anus there are sixty or more 
papillae on either side of the body, extending forwards to about 3-5 mm. 
from the posterior end. These papillae are placed in a very regular row 
immediately before the anus, but their arrangement becomes much 
more irregular on passing forwards, giving an appearance as if two or 
more rows had been broken up and confused. 
The spicules (PI. XVII, fig. 1) are equal in length (2 mm.) and 
resemble in shape those of A. decipiens. 
The tail of the female is even shorter and blunter than that of 
A. decipiens. The anus is situated at 0-2 mm. from the posterior end. 
The tip of the tail is slightly indented, and without a terminal spike. 
The vulva is situated near the middle of the body. In a specimen 
measuring 48 mm. in total length, it opens at 25 mm. from the anterior 
end. The uterus and its two posterior horns are proportionally longer 
and narrower than in A. decipiens, and the whole organ is much con¬ 
voluted. The horns, moreover, instead of being considerably shorter 
than the undivided portion, are about equal to it in length. 
The ova are spherical, and measure 0-04-0-05 mm. in diameter. 
The host of this species was a seal from the Antarctic regions, but 
unfortunately its precise determination is unknown. 
