1912.] N. AnnandaIvE : Reptilia. 55 



III. Apparently endemic species .. 6=14% 



IV. Species only known hitherto fiom Assam 7 = 16*5% 

 V. Assamo-Burmese species .. .. 3= 7% 



VI. Himalayo-Assamese species . . 3 = 7% 



VII. Species only known from Assam and 



Peninsular India .. .. 1= 2'5% 



There are no exclusively Himalayan species in the list and 

 none that have hitherto been known only from Burma. If we 

 compare this analysis with that of the Batrachian fauna of the 

 Abor Hills published on p. 35 of this volume, the chief apparent 

 difference is that the endemic forms appear to be fewer and the 

 representatives of what I have called elsewhere the Malayo-Hima- 

 layan fauna much more numerous. This may be due in part to 

 the fact that the lizards and snakes of Assam are much better 

 known than the frogs and toads, and in part to the wider distribu- 

 tion of species in the former groups. In the main the results are 

 strictly comparable in what may be regarded as their essential 

 feature, viz., in illustrating the non-Himalayan nature of the Abor 

 fauna. Unfortunately we know almost nothing of the reptiles 

 and Batrachia of Bhutan, but the little that we do know would 

 suggest that the eastern boundary of the true Himalayan fauna is 

 formed by the R. Tista, which flows down south through the 

 Himalayas to the west of Bhutan. This river, at any rate in its 

 present course, is apparently a much more ancient one than the 

 existing Brahmaputra. 



The reptiles of the extreme east of the Himalayas, although 

 they have strong Assamese affinities, are by no means identical 

 with those of the Khasi Hills. It is particularly noteworthy that 

 the species of Japaliira which occur in the Dafla Hills is not 

 nearly so closely related to the common /. variegata ^ of Sikhim as 

 that species is to /. planidorsata of the Khasi Hills, and none of 

 the six apparentl}^ endemic species have, so far as we are aware, 

 close allies in the other mountains of Assam. 



We may say therefore that the reptiles of the Abor foot-hills 

 agree with the Batrachia in differing considerably from those of 

 the foot-hills immediately to the west of Bhutan and in including 

 a well-marked endemic element, but that they appear to be more 

 closely connected with the fauna characteristic of the damp jungles 

 of the E. Himalayas, Assam, Burma, Indo-China and the Malay 

 Peninsula. It is to this fauna that it is convenient to apply the 

 term ''Mala3^o-Himalayan," Probably the comparative dryness 

 of the forests on the foot-hills west of Nepal has prevented many 

 damp-loving animals of Malayan origin from penetrating further 

 afield in a westerly or north-westerly direction, while a smaller 

 contingent has been stayed by the course of the R. Tista. 



1 I was wrong in stating that this species occurs in Assam (J.A.S.B., 1905, 

 p. 92), having been misled by badly preserved specimens of /. planidorsatn. 



