62 Records of the Indian Museum. [VOLE Ve 
sete varies from ‘I5 mm. in the anterior to ‘13 mm. in the 
posterior part of the body. I have not been able to recognize any 
difference in type between the sete of the anterior and posterior 
segments. There are usually four or five sete in each ventral 
bundle. 
The dorsal sete are of two kinds, long slender hair-sete, and 
short straight singly-pointed needle-setze. The hair-sete are quite 
smooth; they begin in the same segment as the gills, within which 
they are at first contained; two such sete usually extend into each 
gill, of which one, somewhat longer than the other, may reach very 
nearly to the tip of the gill; like the gills themselves, their length 
will thus be, in extreme cases, considerably more than a milli- 
metre. 
At a varying distance from the anterior end, about the 
fortieth to the fiftieth segment, the hair-setee begin to project freely 
from the surface of the body; as a rule, however, only one of each 
bundle does so, rarely two; the gills still contain a seta, a com- 
paratively short one however, in correspondence with the shorter 
gills. The first free dorsal sete are longer than the gills they 
accompany: ¢.g., the sete may be ‘51mm. long, the gill -4mm.; 
but the disproportion may be much greater—setze °88, gill :28; or 
setee 5, gill “144mm. ‘These hair-sete, like the gills they accom- 
pany, gradually decrease in length posteriorly, though not so. 
markedly as the gills. The needle-setze, usually two per bundle 
occur along with the hair-setze as short pointed rods scarcely pro- 
jecting beyond the level of the body-wall. I have not seen any 
sickle-shaped setze, as described for Branchiodrilus. 
It has been mentioned that the gills are ciliated; these cla 
are extremely fine and delicate, and though sometimes visible 
without much difficulty, are frequently only to be recognized by 
the movements of small particles in the water in their vicinity. 
Similarly over the general surface of the animal; the whole body 
seems to be ciliated, though the cilia themselves are only occasion- 
aliy to be discerned ; their presence is however evidenced by the 
commotion of minute particles in the water near the surface of the 
body. 
The body-cavity is traversed by well-marked septa ; these are 
perforated in places, allowing the lymph-corpuscles to pass from 
segment to segment. These corpuscles are round, and very 
granular; they are not pigmented. 
Alimentary canal_—The mouth cavity is ciliated; the pharynx, 
an oval dilatation, occupies the first few segments, narrowing 
about segment vii to become the cesophagus. ‘This is a straight 
tube continued posteriorly into the intestine; there is no sharp 
demarcation between these, and it is difficult tosay where one ends 
and the other begins. Antiperistaltic movements are frequent, and 
may be violent, in the intestine; they may extend as far forwards 
as the tenth segment. A postero-anterior ciliary action may occur 
in the intestine of these worms, similar to that observed in Nats, 
Pristina, Slavina, etc. 
