iS8 The Scottish Naturalist. 



these brown butterflies zigzagging to and fro in every direction 

 became, as it were, a dreadful nightmare ; and even yet, by an 

 effort of the imagination, I can recall' the feeling of dizziness that 

 the constant pendulous motion of the insects produced. The 

 other butterflies of the glen are about ten or eleven ; not a large 

 number, but still just what might be expected. The rarest is 

 Erebia epiphron, the only truly mountain butterfly that we have 

 in Britain. This has been found in several places in the glen, 

 ranging from 1500 to 2000 feet; but hitherto only in small num- 

 bers. About 1500 feet seems to be the lowest altitude at which 

 it dwells ; but once in Rannoch I found a specimen as low as 

 700 feet. As, however, a lot of sheep had been driven off the 

 higher ground the previous day, I imagine that the butterfly had 

 got entangled in the wool on some ' sheep's back and been 

 brought to the lower level involuntarily. The other butterflies 

 that have been noticed in the glen are Comonympha Pamphihis, 

 C. Davits^ Pieris brassicce, a stray specimen from the cultivated 

 ground wandering, as is often the habit of the species, over the 

 moors in search of fresh fields and pastures new ; Argyiinis 

 Aglata, A. selene, Vanessa urticce, which seems to follow its 

 food-plant, the nettle, wherever it goes, and that is wherever man 

 sets up a habitation. Far away up the glen. of the Tarff there is, 

 in the very heart of the hills, a small house known as the Tarff 

 bothy, and inhabited only for a month or so in the deer-stalking 

 season. No proper road leads to it, and I daresay there are few 

 more lonely and desolate habitations anyv/here in Britain. Yet 

 here, at an altitude of 1800 feet, there was, in July last, more than 

 one specimen of Vanessa urticce lying dead in the window, and 

 outside, sure enough, was a patch of nettles. Lyconia Icarus and 

 Z. Artaxerxes — which, as its food-plant, Heliantheninni, \s com- 

 mon, is likewise abundant — complete the list of butterflies. 



In noticing some of the moths of Glen Tilt I should premise 

 that when " in the woods " is given as the habitat, the lower part 

 of the glen is meant. Most of the species to be mentioned, 

 however, occur close to Forest Lodge, a large majority of them, 

 including even such alpine species as Psodos coracina, halving 

 been taken within very little more than half a mile from the 

 house. That the valley between Blair-Athole and Forest Lodge 

 is tolerably rich in species may be gathered from the fact, that on 

 the 1 8th of last July, not by any means a particularly good day 

 for collecting, upwards of 80 species of Lcpidoptcra were noticed 

 in the ten miles' walk. 



