74 Records of the Indian Museum. [VoL. V, 
chloragogen cells covered the alimentary canal as far forwards as 
septum 6/7 (plate viii, fig. 5). 
Circulatory system.—The dorsal vessel was attached to the 
alimentary wall as far as septum 6/7, where it became free. The 
ventral vessel was non-contractile, was quite separate from the 
intestine except posteriorly, and gave off segmental branches to the 
intestine, which entered a ventral intestinal sinus, or median 
vascular channel in the intestinal wall. Posteriorly, at a little 
distance in front of the hinder end of the body, the ventral vessel 
became joined to the wall of the intestine; finally it bifurcated, 
the two branches curving round dorsalwards and then gently 
bending inwards to unite and form the posterior end of the dorsal 
vessel. Before meeting, they branched once or twice; the branches, 
however, soon re-united (plate viii, fig. 7). 
There were, as a rule, five lateral commissural vessels connect- 
ing the dorsal and ventral vessels in the anterior part of the body ; 
of these, the first was in segment vi, the last in x; the largest was 
that in vii, the next largest that in vi, then those in viii, ix, and x 
in the order given. Several variations, however, were observed ; 
in one case the first lateral vessel was in segment vii; in another 
case, in addition to the five usual vessels, there was also a small ves- 
sel inv; in another case there were four only, in segments vi-ix. 
All these vessels were contractile. 
The blood is red. 
Nephridia.—The first nephridium occurred in the seventh seg- 
ment ; but here again there were variations. Thus in one case the 
first nephridium was in segment viii; in another, the first was in 
vii as usual, but the eighth segment had no nephridia. 
It will be apparent, on looking over a list of species of the 
genus Deyo, that the presence of palps at the hinder end of the body 
excludes the present form from all species, except vaga, stuhlmannt, 
furcata, tonkinensis, schmardai [7| and palustris ({8], Aulophorus 
palustris}. The form of the dorsal setee excludes it from D. stuhl- 
mannt, vaga and tonkinensis ; in D. schmardai the dorsal sete begin 
in segment vi, the ventral sete are far more numerous in segments 
ii-v, and the gill-processes are fewer; D. palustris has many more 
segments (50), and a larger number of gills (4 or ? 5 pairs), but this 
last form still awaits complete description. 
The form to which the animal now described approaches most 
closely is D. furcata, Ok. The differences appear to be the follow- 
ing: the palps are much longer in D. furcata, appearing in 
Bousfield’s figures ({4], figs. 17 and 18) to be. relatively to the 
diameter of the animal about three times as long as in the species 
here described ; the gills also are longer, slenderer and almost cylin- 
drical, in three pairs, of which one pair are ‘‘ secondary branchie,”’ 
_1.€., projections of the margin of the funnel only. Further, the 
present form differs in a number of characters from all the other 
species of the genus, according to the diagnostic summary given 
by Michaelsen [5]. Thus, according to his definition of the 
senus— 
