206 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. XL 



these hills, which are richly forest-clad on their northern slopes, many 

 rare species not obtained elsewhere in our area are found. The valleys 

 leading into the Ganges river on the east and the Jumna river on the 

 west are also excellent hunting-grounds. We have included in our paper 

 all the butterflies brought in by the native collectors gent by us to the 

 highest valleys and hills right up to the frontier of Hundes or Thibet, 

 where the butterfly season is very short, extending at the most from the 

 middle of June to the middle of August. These elevated regions (the 

 N ilung Pass is well over 18,000 feet elevation) are often above the forest 

 line, so that the butterflies found in them all live in the larva state on 

 grasses and low herbaceous plants, for instance the three species of 

 Pamassius enumerated below feed on Sedum and allied moss-like plants. 

 To the south of Mussoorie lies the large triangular-shaped Dehra Dun 

 Valley with an area of 1,193 square miles, and an average elevation of 

 about 2,000 feet. The valley still contains much forest, especially of 

 the valuable sal-tree (Shorea robusta, Gsertn., Natural Order Diptero- 

 carpece), and is watered by numerous perennial streams, which become 

 raging torrents in the rains. The valley is bounded on the north by 

 the Himalayas, on the south by the Siwaliks, on the east by the Gan- 

 ges, and on the west by the Jumna. As will be seen from the list 

 below, many species of butterflies are found in the Dun which do not 

 occur at all in the hills to the north, these species being mainly peculiar 

 to the plains of India. In the Dun the best time for collecting is from 

 July to October, the spring and early summer being far less rich. 

 Even in the winter months, from November to February, a few more 

 or less worn and faded butterflies are on the wing. 



No list has as yet appeared of the butterflies of Mussoorie and 

 neighbouring regions, though many papers have been written on the 

 butterflies of other portions of the Western Himalayas. The principal 

 of these are : — 



I. " Kaschmir, und das reich der siek." Von Carl Freiherrn vOn 

 Hugel. Vol. IV, Part V. * Lepidoptera, pp. 397 and 403-496, 



* la Mr. W. F. Eirby's " A Synonymic Catalogue of Diurnal Lepidoptera " (1871) this 

 part is referred to as the second, but it really is the fifth. Part I is the " Register und 

 Glossarium ; " Part IF'Astrologie der Hindu ; " Part III " Sammlung baktriscber MUnzen ;" 

 Pan IV " Fisphe Kaschmir's ; " Part V "Insecten" by Vineenz Kollar und Dr. Ludwig 

 Eedtenbacher. Two other parts devoted to " Sangthier-Fauoa von Kaschmir, '.. and 

 " Hochsten Macht des Sick-Eeiches " complete the volume. 



