H. A. Baylis 
363 
The posterior end of the body is thicker than the anterior, and does 
not taper so gradually. The tail (PI. XVI, fig. 2) is short, and rounded 
behind, except for a small tail-spike at the extreme tip. In a specimen 
9 mm. long, the tail ( i.e. the portion of the body behind the anus, 
including the terminal spike) measured 0-09 mm. In another, about 
15 mm. long, the tail measured 0T5 mm. It thus measures about 
of the total length of the body. In the two cases quoted the tail-spike 
measured 0-020 mm. and 0-025 mm. respectively. The cuticle of the 
tail-spike is generally transversely wrinkled, its appearance suggesting 
that it is capable of a certain amount of extension or contraction. 
The alimentary canal (PI. XIV, figs. 1-3) provides the most satis¬ 
factory specific characters, and it is to this that I wish to draw special 
attention. The oesophagus is divided transversely into two portions of 
quite different appearance. Anteriorly (Oes. 1 ) it possesses the usual thick 
muscular walls and narrow lumen characteristic of nematodes in general. 
This portion measures from about i to of the total length of the 
worm; that is to say, it is longer, proportionally to the body, in the 
younger individuals than in the older. Thus in a specimen 9 mm. long 
the length of this part of the oesophagus is 1-026 mm. In a 15 mm. 
example it measures 2-16 mm.; in another of 28 mm., 2-43 mm., and 
in an older specimen, 38 mm. long, 3-24 mm. This portion of the 
oesophagus is gradually but slightly thickened towards its hinder end. 
The posterior division (Oes. 2 ) of the oesophagus is a somewhat 
oblong organ with very thick walls of granular appearance, which are 
very opaque even after clearing in creosote. Von Linstow has considered 
this organ to be of glandular nature, calling it a “Drusenkorper,” and 
has given a figure of it (1884, PL VII, fig. 5, b), which, however, gives 
only a somewhat vague idea of its appearance. In the specimens that 
I have studied it appears evenly granular, and I have been unable to 
distinguish cell-boundaries or nuclei in its walls. It extends somewhat 
further back on the ventral than on the dorsal side. There is probably 
a narrow passage through it connecting the anterior portion of the 
oesophagus with the chyle-intestine, though it sometimes appears 
almost solid. It measures, in an example of 9 mm., 0-38 mm. in length; 
in a 15 mm. example, 1 mm.; in a 28 mm. specimen, 1-2 mm.; in one 
of 38 mm., 1-2 mm. It is evident, therefore, that it does not continue 
to increase in size in proportion to the growth of the individual. 
The chyle-intestine ( Int .), in the youngest examples studied (9 mm.), 
appears solid, and is composed of large polyhedral cells which become 
perfectly transparent and colourless when the specimen is immersed in 
