1865-3 Note relating to Sivaltk Fauna? 63 



understood — not so in former times. This dark child a little darker 

 than the others separates with a few more from the rest of the family 

 and sojourns in a land where a hot sun emhrowns them with a still 

 deeper hue. In time they hecome blacker and blacker or browner and 

 browner. Should they travel north instead of south, it is all the same ; 

 for extreme cold produces the same effect as extreme heat ! This is 

 ancient and modem physiology !" 



Note relating to Sivalih Fauna. — By II. B. Medlicott. 

 [Eeceived 7th September, 1864.] [Read 7th September, 1864.] 



The notice I have to bring before the Society may be considered a 

 continuation of a series of brief but important communications, com- 

 menced more than thirty years ago, and continued during some twenty 

 years, as recorded in the volumes of the Journal of the Asiatic Society 

 for that period. Those communications formed a current chronicle of 

 the discovery of the Fauna Sivalensis. Had the account of those 

 discoveries ever assumed a more connected and complete form, the 

 correction I have now to make, would never have been needed, as it is 

 but the statement of a fact, of which the evidence was in hand and in 

 mind, although never expressed. Indeed, for the same reason, this 

 fact can now be only indicated, its value being still unknown. This fact 

 is — the existence of two vertebrate faunas, possibly quite distinct, 

 among the fossils hitherto collected from the so-called Sivalik rocks. 



In a recently published number of the ' Memoirs of the Geological 

 Survey of India, Vol. III. Part 2, I have given a somewhat detailed 

 account of the geology of the Sub-Himalayan region in North- West 

 India. I therein established a threefold division of the great series of 

 deposits coming under the general title of Sub -Himalayan. Concerning 

 the lowest of these groups (Subathu, etc.) little or no conflict- 

 ing evidence presented itself. The two upper groups I described 

 as in all respects more akin to each other, although still most 

 clearly separable along a well marked boundary, at which the younger 

 strata overlap the steeply denuded edges of the older, besides being 



