a a 7. 5.] Notes on the Freshwater Fauna of India. 189 
S 
ally in the genus Ohetoyaster, The last (Fig. 1B) is remarkable 
for possessing in the brain a sensory organ which is densely 
pigmented and probably Past le as an eye. The buccal cavity 
in this species is very deep, the muscular pharynx short; the total 
length is from 2 to 3 mm., and there are not more than eight 
pairs of setigerous bundles, the sete resembli ing those of Cheto- 
gaster benyu/ensis in arrangement, but being fewer in each bundle. 
Except those just behind the mouth, they are not retractile. The 
vascular plexus is better developed than in the two other 
forms I have examined, and extends forwards to the base of th 
buccal cavity. There is no nephridium near the i peste but 
that which opens at the base of the third bundle is han 
those posterior to it. Although the sexual organs are po 2 imma- 
ture, the clitellum is well developed. 
The food of this form with an eye consists, at any rate in part, 
of the Protozoa ( one yen mere ks Stentor, etc.) which are me 
dant on the surface of t oarium the Polyzeon. The 
hooks itxelf along with tha aid of its sete, the first Rete 
playing no part in progression but being used to seize and 
the Calcutta “tanks ”—I have no Sipe able to find specimens 
this winter—this Eyed Ch seabicnatal progress through the 
water without support, by igen a rerital contortions of its 
body ; but it prefers as a rule to crawl. 
Fic, 1. Two species of Chetogaster from Plumatella, April. 
A=Ch. xpongilla. B=Ch.,sp. (Both x about 35.) 
B=buad. C=clitellum; e=eye; 0=otocyst. Both specimens are in a state 
of contr. ct’on. 
