278 [December, 



special spot, a trait which we frequently remarked in this butterfly. 

 It likes steep, sunny, rock faces, and is much easier to catch in the 

 afternoon than in the morning, when it is apt to haunt the higher 

 rocks and to fly very wildly. 



March 20th found us back again at Biskra, and again we tried 

 the Beni Mora, found L. Lysimon and L. Theophrastus still flying, 

 and nothing much else that was worth catching. I was fortunate 

 enough to fall in with Prof. Max Korb. the well known Munich col- 

 lector, and he told me that M. Didyma var. deserticola was out, and 

 to be had in plenty at the foot of the mountains about three miles 

 south-west of Biskra ; so we arranged an excursion there for the next 

 day, which fortunately proved fine, and took a good series of the var. 

 deserticola flying in and around the dry beds of streams where they 

 meandered along the stony flats at the foot of the ridge. Having se- 

 cured as many deserticola as we wanted, and also several pupae of 

 Psyche quadrifasciaria, we proceeded to explore the mountains close 

 above us, and found them very steep and bare. After taking a few 

 common insects, and scrambling a long way across the rocks, I caught 

 a specimen of the butterfly I had previously supposed to be E. 

 Fallout, but Prof. Korb joyjully exclaimed that it was T. Nouna, 

 which he had never before met with ! This was a revelation to me ! 

 I had taken a good many, and had hitherto imagined that the delicate 

 orange edged beauty was F. Fallout, and not the rare T. Nouna. Prof. 

 Korb presently secured another specimen, and then I found a good 

 hot corner where I took five or six, but all rather worn. 



I now began to enquire what Falloui was like, and Prof. Korb 

 kindly showed me a specimen taken by him at Biskra a few days 

 earlier ; he assured me that if I had lately been taking Belemia in any 

 number it was tolerably certain that I had got Falloui also, the two 

 butterflies being so much alike that it is difficult to distinguish them 

 in the net. This proved to be the case ; I found a good series of 

 Falloui among my captures when I came to have them set. 



Next day we started in a gale of wind for a desert lake called 

 Gilga, about six hours' march westwards from Biskra ; but when we 

 reached our point we found the lake almost dried up, and could not 

 approach what water remained on account of tamarisk scrub and mud 

 and quick-sands. A regular disappointment ! However, we found 

 good camping ground and good pasture for the animals, and next day 

 made a successful excursion to a desert ridge to the southwards. 

 Very bare rocks and very few insects of any sort ; but in the after- 



