1910.) J. STEPHENSON: Aquatic Oligocheta of the Punjab. 61 
anterior segments they decrease somewhat in size, and become 
progressively smaller and smaller; about the fortieth segment 
they may be only ‘4mm. long, about the fiftieth -3mm., and after 
the seventieth they are mere tubercles. These figures are approxi- 
mate only, and are given for the sake of illustration, as there is 
a certain amount of individual variation. The processes are how- 
ever recognizable, though as minute tubercles only, till within 
quite a short distance of the growth zone at the posterior end of 
the body; in this respect the present form seems to differ from 
Branchiodrilus, where, according to Bourne’s figure, there may be 
as many as sixty-seven posterior segments without any recogniz- 
able processes. 
In an animal which was preparing to divide asexually, the 
anterior portion of seventy-nine segments had recognizable gills 
throughout its length, the most posterior, just in front of the 
budding zone, being "13mm. long. The first gill of the posterior 
animal was *35mm. long, the second -48mm.; as above, small 
tubercle-like processes were visible to within a short distance of 
the hinder end, practically as far as distinctly differentiated seg- 
ments were to be recognized. 
These processes in the anterior part of the body contain the 
dorsal hair-sete ; they are, like the general 
surface of the body, ciliated; they present 
here and there short stiff hairs, presum- 
ably sensory; they are hollow, and 
body-cavity corpuscles may be seen mov- 
ing into or out of them; they contain 
two well-marked blood-vessels, one 
PHO ep ibeties 2 h.2 afferent and one efferent. They are 
shape of eae al a ee usually regularly cylindrical in shape, but 
in Lahoria hortensis. occasionally show irregularities of outline, 
and there may be a tendency to forking 
at the free end (text-fig. 1); they are somewhat constricted at 
their attachment to the body-wall. They. are in the natural 
condition stiffened by the contained sete, but 
appear to possess a certain amount of contractility, 
since in fixed and preserved specimens the long 
anterior processes are usually found much curved, 
often into the shape of a semicircle. ~ 
The set@, except in the most anterior region, are 
in four bundles per segment, two dorsal and two 
ventral. The ventral sete (text-fig. 2) begin in the 
A 
TIN 
second segment; they are of the usual | -shape, 
forked distally , the two prongs being equalin length, 
the proximal prong, however, being twice as thick 
a at its base as the distal. The nodulus is slightly 
ac noe distal to the middle of the length of the seta, the 
Lahoria horten- proportions of the proximal and distal parts of the 
sts. seta being 7:60r8: 7. The total length of these 
SS, 
