XXIX. OLIGOCHAETA. 



By J. Stephenson^ D.Sc, Major, I. M.S., Professor of Biology- 

 Government College, Lahore. 



(Plates xxvi-xxvii). 



INTRODUCTION. 



The interesting collection of earthworms here described was 

 made in Assam and the Abor country, on the occasion of the 

 recent Abor Expedition (1911-12), by Mr. S. W. Kemp of the Indian 

 Museum, the naturalist with the expedition. The leading features 

 of the collection may be briefly summarized. 



Twenty-one species, and in addition one variet}', are re- 

 presented ; of these no fewer than eighteen, and the variety just 

 alluded to, are new. Ten of the new species are represented only 

 by single specimens, or at any rate by single mature specimens. 

 In addition, a few specimens were indeterminable, or determinable 

 only as regards the genus. 



The species are distributed among seven genera, Drawida, 

 Plutellus, Megascolides, Notoscolex, Perionyx, Pheretima, and Eu- 

 typhoeus, all of which are known in India. 



In the case of many of the species, the habitat presents no 

 peculiarity ; they were found in earth, under stones, while road- 

 making, etc. The genus Perionyx, how^ever, appears to choose 

 other sites ; the various species were frequently found in rotten 

 wood, or under bark, while P. depressus was found at the base of 

 the leaves of the plantain and screw-pine, ten, fifteen, or twenty 

 feet from the ground. This peculiarity is not unknown in the 

 genus, the name arbor icola having already been applied by Rosa 

 to a species from Burma. The two species of Pheretima were also 

 found in rotten wood or under logs. One species of Drawida was 

 found under a stone in water. 



I may here draw attention to a peculiarity which occurs seve- 

 ral times in the collection,— the forward displacement, by one 

 segment, of the organs of the anterior part of the body. This has 

 occurred in the single specimen of Megascolides, and in the speci- 

 mens of both species of Notoscolex. With regard to the Megas- 

 colides, the peculiarity may be merely individual, since in the 

 absence of other examples it is impossible to say whether it extends 

 to the whole species or not ; though, on the analogy of Notoscolex 

 striatus, it may not improbably do so. 



In the case of Notoscolex the value of the variation is also not 

 easily to be determined. It occurs in the species striatus in three 



