386 Records of the Indian Museum. [Vol. VIII , 



Perionyx excavatus, Perrier. 



Dibrugarh, N.E. Assam, in rotten wood; 2o-xi-i9ii. A number of 

 specimens, many of small size and immature. 



Sadiya N.E. Assam, under logs; 25-xi-igii. Ten specimens, a 

 number mature. 



Same place and date, under logs ; two other specimens. 



Again same place and date, under logs ; two other specimens. 



Rotung, alt. 1300ft., in rotten wood; 2S-xii-i9ii. Numerous immature 

 specimens, probably of this species. 



Renging, Abor country, under bark ; ig-xii-igii. Six specimens. 



Upper Rotung, alt. ca, 2000ft., under bark ; 9-i-iQi2. Numerous speci- 

 mens, a voung brood probably of this species. 



The Renging specimens were extraordinarily small, their maxi- 

 mum length being one inch, and maximum breadth 2 mm. ; male 

 apertures and genital setae were however present. Compare 

 Michaelsen's remarks on variability in size (3, p. 175). 



The clitellum in the Dibrugarh specimens was only distinguish- 

 able by its rather lighter colour ; it extended over segments xiv- 

 xvi = 3. In the specimens from Sadiya and Renging it was absent 

 altogether. 



The midventral break in the setal ring varies in different 

 specimens ; it may be absent altogether, or may be well-marked 

 {aa = 2ab). 



In the specimen which I dissected (one from Dibrugarh), 

 I found that the nephridia pierced the bod3^-wall at approximately, 

 but not quite equal distances from the mid-ventral line. The 

 prostates were compact, and sessile on the body- wall. The sper- 

 mathecae were large ovoid sacs, with short and narrow ducts, and 

 without diverticula. 



Perionyx annulatus, sp. nov. 



South of Vembung, Abor country; ii-ii-iyi2. A single sexually mature 



specimen. 

 Rotung, Abor country, alt. 1300 feet, under stones ; S-iii-1912. Several 



specimens, but only one mature. 



The specimens show many individual differences. The single 

 example from the first locality, though mature, was abnormal in 

 many respects ; the mature specimen from the second localit}^ was 

 much softened and broke in two before the examination was com- 

 pleted. Though the male apertures were indicated in a third 

 specimen, their position here too was abnormal, and internally 

 sexual organs were found not to have developed Of three other 

 immature specimens, one was much softened, one was mutilated 

 in the anterior part of its body, and one had its hinder end re- 

 generated. The description which follows applies to the mature 

 specimen from the second locality, supplemented, on account of 

 its bad preservation, by the examination of the abnormal speci- 

 men from the first locality (with the necessary allowances for the 

 extra segments in the latter). 



Length 4-6 inches; diameter 4-6 mm. Ventral surface pale ; 

 dorsal surface in general a dusky purple, but when examined more 



