260 SPOLIA ZEYLANICA. 



side in each segment (except I. and XII.) ; the singly pointed seta 

 thinner than the forked one, and without nodulus ; the outer prong 

 of the forked seta much smaller than the inner, the nodulus markedly 

 distal. Vas deferens enters atrium at the proximal end of the latter. 

 Spermathecse ovoid, with long narrow ducts ; spermathecal aper- 

 tures ventral 



Ceylon (Nuwara Elij^a). 



LiMNODRiLUS sociALis, Stephenson. 



This worm occurs twice in the present collection, both batches 

 of specimens having been taken at Kandy (hill country, 1 ,600 feet). 

 In one case Dr. Annandale notes that " these worms were Very 

 numerous in the mud at the bottom of a pool of very dirty water in 

 a disused tunnel frequented by bats." The other tube contained 

 also the specimens of Dero zeylanica and Aulophorus palustris 

 (v. ant.) ; these " were taken in the mud left in a small depression 

 in the bed of a bathing-pool formed by the overflow of the Kandy 

 lake. The pool had just been emptied in order that it might be 

 cleaned, and the worms must originally have been in 5 or 6 feet of 

 water." 



The rarity of Tubificidse throughout the whole of the Indian 

 region (only three species having been so far recorded), and the 

 striking similarity in behaviour, has caused me to suspect that this 

 species may be that referred to by Willey in his recent book on 

 " Convergence in Evolution " (13). Writing of the similarity in 

 appearance and habits between the larvse of Chironomus and the 

 Tubificidse, he says of the latter (with special reference to an 

 unnamed species of Limnodrilus from Ceylon) : — " They keep the 

 head and fore-body buried in the mud, whilst the hinder portion of 

 the body, through which respiration is effected, is kept constantly 

 waving as near the surface of the shallow water as possible. When 

 alarmed, an entire colony will instantly withdraw out of sight into 



the mud as with one consent Limnodrilus, as observed by 



me in Ceylon, forms dense aggregates of individuals surrounded by 

 mud, but does not form definite tubes which can be isolated from 

 the clumps." 



The above has such a striking resemblance to my original 

 description of the habits of the worm as observed at Lahore (11), 

 that, with these specimens, also from Ceylon, before one, it is 

 difficult to believe that the species are not the same. 



This worm is apparently widely distributed in the East ; I have 

 received specimens from Calcutta also. When in Kashmir last 

 summer I saw, in a pool at Baramula, a colony of what I believe to 

 have been this species; though, as I had of set purpose omitted 

 to take any apparatus with me, this remains for the present a 

 conjecture only. 



