748 Rccot'ds of Ihe Indian Museum. [Vol. XXII, 



the other, — the reverse is the case in most other genera of the 

 family. 



A second species was described in 1906 by Piguet (10), who 

 placed it among the Naididae as Naidiuiii pluriscta, but later (11) 

 transferred it to Aulodrilus. 



The justification for the inclusion of these species in the Tubi- 

 ficidae is to be found in the absence of asexual reproduction by 

 fission, which is a constant characteristic of the Naididae; as well 

 as, perhaps, if .4. pluriseta resembles ,4. lininobius and A. remex, 

 in the presence of large parietal vascular loops at the hinder end 

 of the body. It must however be owned that if. as Piguet states, 

 an Avlodrilus from the S. of France, the study of which was not 

 completed when he wrote, has retractile penes in front of the ven- 

 tral setae of segment vii, the genus is probably nearer to the 

 Naididae than to the Tubificidae, though capable of inclusion in 

 neither ; and Michaelsen's caution in placing Aulodrilus as a doubt- 

 ful genus (of Tubificidae) (6) is justified. 



A. liinnobius and .4. pluriscta form tubes, as does perhaps, to 

 judge from the foreign matter which adhered to the present speci- 

 mens the Indian species also. The hinder end of both A. pluriseta 

 and the present species (and, it may be conjectured, A. liinnobius 

 also) is remarkable ; the most posterior region shows no prolifera- 

 tion, nor even any segmentation; but there is a zone of prolifera- 

 tion and formation of numerous new segments some little distance 

 in front of the anus. These zones are known in other worms in 

 two situations ; — terminal, in probably all Oligochaetes and other 

 segmented worms which continue to produce new segments during 

 their life; and in the middle of the body, in Aeolosoma and the 

 Naididae, where such a production of new segments (a " liudding 

 zone") indicates the site of approaching fission. Such a budding 

 zone as that of the present genus is, so far as I know, unique. 



The terminal unsegmented region Piguet looks on as physio- 

 logically a gill ; it possesses a rich cutaneous vascularization ; and 

 during life the anus can dilate, giving rise to a " branchial fossa." 



Some interesting species in the collections. 



Drawida raui, sp. nov., described below is interesting from the 

 fact that it possesses a well-developed pair of prostates in segment 

 ix, equal in size to those in segment x. The anterior pair have no 

 direct communication with the male reproductive apparatus, while 

 the posterior are, as usual, joined by the vasa deferentia. Mich- 

 aelsen has previously (7) found a rudimentary second pair in seg- 

 ment ix in D. ivillsi, and has argued that the genus originally 

 possessed two fully-developed pairs, of which the anterior has dis- 

 appeared. This anterior pair, in turn, is the index of a formerly 

 existing second pair of testes, the ancestors of the genus Dratvida 

 having been holandric while their present-day representatives are 

 metandric (retaining only the posterior of the two original pairs 

 of testes). The genus Desinogaster (Burma, Sumatra, Borneo) is 



