228 Records of the Indian Museum. [Vor: Valle 
of Bourne’s worm. It does not seem possible, on the other hand, 
that Bourne should have overlooked the occasional occurrence 
of prebranchial ventral setae, since he “‘ secured numerous speci- 
mens of Chaetobranchus’’ and (with regard to the mode of 
asexual reproduction at least) ‘‘examined a very large number of 
individuals.”’ 
The two forms are therefore to be regarded as distinct, 
and I accordingly propose for the one herein described the 
specific name menont. It seems however impossible, merely 
on the ground of a (far from constant) difference with regard 
to the prebranchial setae, to deny a close genetic relationship 
between the two. They must undoubtedly be regarded as belong- 
ing to the same genus. 
For the generic name Chaetobranchus, which, since it is 
the name which Bourne used, has been employed above in refer- 
ring to the worm described by him, Michaelsen (8) substituted 
Branchiodrilus, Chaetobranchus having been previously used fora 
fish. The new worm thus becomes Branchiodrilus menont. 
If however these two species are ranked under the same 
genus, so must be the form from Lahore described by me as 
Lahoria hortensis (15) ; since the reason for separating this latter 
as a distinct genus from Bourne’s worm was the same difference 
with regard to the prebranchial setae which occurs or may occur 
in B. menont ; i.e. the fact that four (or three) pairs of ventral 
setal bundles may occur in front of the first gills, or rather (which 
comes to the same thing) in front of the first dorsal setae. 
The genus therefore now comprises three species, and genus 
and species will be defined as follows :— 
BRACHIODRILUS Mchlsn. (= Chaetobranchus—Bourne) : 
Prostomium rounded. A pair of dorso-laterally placed 
branchial processes on many or most of the body-segments, 
beginning immediately or a short distance behind the mouth. 
Ventral setae crotchet shaped, forked distally. Dorsal setae 
beginning in the same segment as the gills, of two kinds, 
capillary and needles; the former, in a number of the anterior 
segments, enclosed in the gills. 
1. B. semperi (Bourne). 
Length 38-50 mm., diam. ‘5 mm.,.segments 130. Branchial 
processes begin in the segment behind the mouth; at first 
are about four times as long as the diameter of the bodv, then 
decreasing in length and disappearing at the 60th—7oth segment. 
Dorsal setal bundles consist of two or three capillary setae, 
longer in the anterior, shorter in the posterior segments, and 
two or three short sickle-shaped setae, the latter wanting in the 
anterior segments. Capillary setae of dorsal bundles all enclosed 
in the branchial processes in about the first 30 segments, some so 
enclosed in about the next 30, thenceforward all free. Ventral 
