64 Records of the Indian Museum. [VOLRVs 
The nervous system has the usual relations. The two halves 
of the cerebral ganglion appear to be more distinct than is often 
the case in the Naidide, and in the living condition were seen as 
two separate ganglia united by a transverse commissure; this is 
not apparent in preserved specimens. 
Asexual reproduction.—In the description of Branchiodrilus, 
Bourne mentions the absence of a budding zone between the two 
components of a chain, and remarks that the process of division 
resembles rather a simple fission of the animal into two. ‘The 
present form, however, shows a distinct, though not extensive, 
budding zone. A reference to text-fig. 3 will illustrate this. The 
specimen had almost reached the stage of complete division; and 
the two components separated, in fact, when the specimen was 
being transferred to balsam. It will be seen that the last bran- 
chial processes of the anterior animal (A) are still of some consider- 
able length, and that the most posterior portion of this animal has 
no branchial processes at all; this last portion, therefore, is evi- 
dently a new production, or the series of branchial processes would 
have been continued over it. Similarly the anterior portion of the 
hinder animal (B); the ventral sete (not shown in figure) are small— 
hence new productions, not a continuation of the original series; 
and, as usual, these anterior segments are without gill-processes, 
which would have been present, and even of moderate size, had 
these segments been a continuation of those of the anterior animal. 
It appears, therefore, that the posterior segments of the 
anterior of two still conjoined animals are produced in a budding 
zone, and that the same is the case with the anterior five segments 
of the posterior component. It is interesting to compare this 
phenomenon with what occurs in Chetogaster [10] and Nats [11]; 
in both these forms the anterior region, comprising five segments 
which are differentiated from the rest by the distribution of the 
setze, is formed as a new production in the budding zone; in the 
present form also these segments are differentiated from the rest 
(by the absence of dorsal sete), and are formed in the budding 
zone; while in Branchtodrilus, where there is no differentiation, 
the budding zone is inconspicuous, being limited presumably, as far 
as the posterior animal is concerned, to the production of the 
prostomium and first segment. Genital organs have not been 
observed. 
Systematic position.—The presence of branchial processes alone 
would not be sufficient to ally this form in any close connection 
with Branchodrilus, since the genus Dero among the Naididz also 
possesses similar organs, and there is no reason to suppose that 
such physiologically similar organs may not have arisen indepen- 
dently. 
But when, in addition to the mere occurrence of branchial 
processes, we consider their distribution in the anterior part of 
the body, their gradual diminution in size posteriorly, their length 
and shape, and the fact that anteriorly they enclose the dorsal 
hair-setz, while posteriorly these sete project freely, we must 
