88 ALFEED GIBBS BOURNE. 



I have found several individuals preparing in this way for 

 fission, but never found any trace of a '' budding zone." At 

 some other time of year I shall, I hope, be able to make further 

 observations with regard to this process, and also with regard 

 to the generative organs. I have hitherto found no trace of 

 generative organs. This is unfortunate, as it leaves the 

 systematic position of the worm still open to some doubt. 



Systematic Position. — This is without doubt the worm 

 referred to by Semper as occurring along with Dero philip- 

 pinensis.i In many details of its structure, as well as 

 in the fact that it exhibits fissiparous reproduction, Chseto- 

 branchus resembles the Naidomorpha, and represents, I be- 

 lieve, a family closely allied to the Naidomorpha (Vejdov- 

 sky) and the Chsetogastridse (Vejdovsky). The most remarkable 

 feature in its structure is, of course, the possession of 

 branchial processes, and these processes are themselves re- 

 markable in completely surrounding the whole or a portion 

 of the dorsal seta bundle. With the exception of the con- 

 tained setae these branchial processes closely resemble in 

 structure the long branchial processes found in the anal region 

 of some species of the genus Dero. 



The only other Oligochaete which possesses branchial pro- 

 cesses is Alma nilotica; but, judging from Vejdovsky's 

 remarks anent this form, it is very different from Chaeto- 

 branchus. 



Generic Description. — Chsetobranchus, g. n. — Capil- 

 lary setae present. Each of the anterior segments, from 

 the second segment backwards, bears a pair of dorso-laterally 

 placed branchial processes, which entirely include some or all 

 of the setae in the dorsal bundle. Dorsal setae commence in 

 the same segment as do the ventral setse, i. e. the second 

 segment. 



Chaetobranchus Semperi, sp. n. — Fresh stagnant water, 

 Madras town. 



I have dedicated the species to Professor Semper, as the 



' ' Arb. Zool. Zoot. lustitut, Wurzburg,' Bd. iv. 



