IG F. Moore — Descriptions of some new Genera and [No. 1, 



attribute to a drainage of cool heavy air from the valleys of the 

 hills surrounding the Punjab and the high lands of Beloochistan and 

 Afghanistan ; air cooled by the precipitation on the mountains. 



If the above view be true, the stillness of the atmosphere, combined 

 with the presence of a moderate evaporation, must be accepted as the 

 condition which primarily determines the formation of barometric minima 

 and the winter rains of Northern India. And this stillness is obviously 

 due to the existence of the lofty mountain ranges which surround Nor- 

 thern India, leaving free access to the plains open only to the south. 



Were the Himalayan chain absent and replaced by an unbroken 

 plain, stretching up to the Gobi desert, it is probable that the winter 

 rains of Northern India would cease ; any local evaporation in the Punjab 

 and Gauge tic valley would be swept away by strong dry N. E. winds 

 blowing from the seat of high pressure, which, in the winter months, 

 lies in Central Asia ; and instead of the mild weather and gentle breezes 

 which now prevail at that season, on the Arabian Sea, it would be the 

 theatre of a boisterous and even stormy monsoon, such as is its local 

 equivalent of the China Seas. Other and even greater changes of 

 climate, that would supervene on the suppression of the Himalayan 

 range and the consequent alteration of the summer monsoon, its preci- 

 pitation, and the course of the land drainage thereby fed, it would be 

 beyond the province of my present subject to discuss. 



II. — Descriptions of some new Asiatic Diurnal Lepidoptera ; chiefly from 

 specimens contained in the Indian Museum, Calcutta. — Bij Frederic 

 Moore, F. Z. S., A. L. S. Communicated by the Natural History 

 Secretary. 



[Received May 14th, — Read June 4th, 1884,] 



Family NYMPHALID^. 



Subfamily Satyrin^. 



Genus Ypthima, Hiibner. 



Ypthima mahratta, n. sp. 



Male and female. Upperside brown ; forewing with a subapical 

 bipupilled ocellus ; between which and the outer margin is a pale brown 

 curved fascia as in Y. newara : hindwing with a very small subanal 

 unipupilled ocellus. 



Underside pale whitish-brown, very numerously covered with short 

 delicate pale brown strigae, which are uniformly disposed : forewing with 



