igoy.] Records of the Indian Museum. 137 



by its bifid anterior end and the median row of buttonliole-like per- 

 forations in its anterior portion which are shown in fig. 11. 



The upward growths of nervous matter within the body-wall 

 at the site of the constrictions have already been mentioned. The 

 cerebral ganglion can be distinguished in the posterior portion some 

 time before this is ready to separate. 



Under an oil-immersion lens the nodulations on the ventral cord, 

 which aggregated together form the ganglia, are seen to consist of 

 spherical hyaline cells with nuclei, placed mostly in the dorsal sides 

 of the cord. 



Sense organs are represented by the tactile hairs, and possibly 

 by the refractile particle in the cerebral ganglion. 



No sexual organs have so far been observed. 



The mode of examination adopted throughout has been the ob- 

 servation of the living animal under the microscope ; its transpar- 

 ency renders this easy. A stained specimen revealed comparatively 

 little of the structure of the animal. 



The predominance of asexual reproduction, together with the 

 presence of a nervous system unconnected with the epidermis, 

 places this form at once among the Naididae. The total absence of 

 hair-setae, of dorsal setae altogether, and of ventral setae also in the 

 third, fourth and fifth segments, would seem further to assign it to 

 the genus ChcBtogaster . The definition of this genus, however, 

 includes a reference to the third segment, which is much elongated in 

 all forms hitherto recognised as belonging to the genus ; while 

 in the form now described the third segment is commensurate with 

 the oesophagus, and of no greater length than the two succeeding 

 segments. In Chcetogaster , also, the longitudinal commissures of 

 the ventral cord are separate from each other in the anterior part 

 of the body ; this can hardly be said of the form now described 

 {v. fig. 11). The definitions of genera include no reference to the 

 alimentary canal, and I cannot say whether or not the' differentia- 

 tion of the parts of the tract which I have called ''crop" and 

 " stomach" occurs in the various species of ChcBtogaster. 



If, in consideration of the similarity in other respects of this 

 form to the species of ChcBtogaster , it should be thought advisable 

 to widen the definition of the genus so as to include it, I would 

 suggest punjahensis as a suitable specific name ; since , besides the 

 characters mentioned above, it differs in its length, or transparency 

 or extent of the oesophagus, or the characters of the circum-cesopha- 

 geal vascular ring, or the number of setae in each bundle, or in more 

 than one of these points, from the several species described by 

 Michaelsen {Olii^ochcBta, 1900) as belonging to the genus. 



