946 MR. H. E. MEHRA ON TWO NEW INDIAN 



Aidodrilus kashi resembles A. remex iu possessing somewhat 

 similar oar-shaped setae in addition to the ordinary needles ; but 

 its hair setae are longer than the needles. The first nephridium 

 lies in the 11th or 12th segment. It is twice as long as A. remex. 

 The genital organs are in segments 6 and 7, the .clitellum is on 

 segments 7 and 8, and spermathecse are in the 6th segment ; the 

 spermiducal chamber occupies segment 7. 



In A. stephensoni there are no oar-shaped needles, in which 

 point it markedly differs from the above species. The needles 

 are here singly pointed and not forked — a point in which 

 it differs from all the other species. The genital organs here lie 

 in segments 9 and 10, the clitellum extends over segments 10 

 and 11 and the spermathecae are in segment 9. The penial setae 

 are the modified ventral setae of the 10th segment. 



(3) AULODRILUS KASHI, Sp. n. 



(a) Habits and External Characters. 



The worms live invariably in tubes formed of small foreign 

 particles of sand and debris cemented together with mucus 

 secreted by the glands in the skin ; in the undisturbed condition 

 the posterior portion generally remains outside the tube in the 

 water, and is waved gently to and fro somewhat like the tail of 

 Tthhifex, Lininodrilus, and other Tubificids, while the anterior end 

 and greater portion of the body remains buried in the tubes inside 

 the mud. On being disturbed, however, the worms withdraw 

 their freely moving tails with fair rapidity. When placed isolated 

 in water, they do not come out of the tubes very readily, but 

 when after a few minutes they do come out, they move like other 

 Tubificids. 



About 40 specimens of this form were obtained between 

 February and April, of which 27 were sexually mature. They 

 vary from 20-28 mm. in length and hence are much larger than 

 A. remex. The hinder end of the worm is much thinner, the 

 diameter being 'IS mm. The diameter near the anterior end is 

 •26 mm. The colour is yellowish-red due to the blood seen 

 through the transparent body- wall. 



The prostomium is bluntly conical, about 90 /x in length. The 

 number of segments varies from 31-70, plus a considerable 

 number of undifferentiated new segments, followed by a narrow 

 terminal region of about '78 mm. in length, which does not show 

 any sign of segmentation (PI. III. fig. 11). The number of new 

 segments forming in the region of budding varies considerably, 

 but it usually is large. The small narrow region behind the zone 

 of proliferation and in front of the wide terminal anus Piguet 

 regards as physiologically a gill. According to him it possesses a 

 rich cutaneous vascular plexus, but this I have not been able to 

 observe in my specimens. The anus can dilate during life, 

 forming what Piguet calls a " branchial fossa." The anus is wide 



