A MONTH IN SWITZEKLAND AND ELSEWHERE. 89 



not in any way interfering with the silver-centred spot which in isis is 

 often absorbed ; the general colouring also of the wing in arsilache is 

 much more purple-red than in either of the forms pales or isis. It is 

 moreover confined to marshy ground and where it occurs in the 

 neighbourhood of isis appears somewhat later ; this however rarely 

 occurs, for arsilache is as a rule to be found at much lower elevations; 

 the fact moreover that when it is found at high levels, such as the 

 Engadine, it still retains the characteristics of the lower altitudes and 

 •does not approximate towards the usual high level forms of pales, is 

 rather a strong argument in favour of its fixity as a species. Nothing 

 however but breeding experiments can absolutely determine the 

 question. 



On returning to Pontresina station I picked up a pair of B. pales, 

 3- and 5 , of the isis form though rather smaller than usual, and 

 then proceeded along the road leading to the Koseg glacier, the 

 species met with here being Polyoiuniatns eras, Albnlina plieretes, 

 Afp'iades coridon, A. thetis, Plebeiiis arfji/roi/nouion, PaDiassias delins and 

 Oeneis a'ello. I crossed over later to the other side of the torrent in 

 hopes of finding Brenthis tJiore snad ]\lelitaea inatiirna wa^r. ivolfensberf/eri, 

 but it was getting late in the day which probably accounted for my 

 failure, as I heard a day or two later that both species were out and 

 not uncommon. 



My second expedition in this direction took me on the 11th to the 

 top of the Bernina Pass direct. There was still a good deal of melting, 

 but as yet unmelted, snow about, and near the station I found nothing 

 but large numbers of Hesperia cacaliae : I netted a great number in 

 hopes of finding H. andtowedae among them but amongst all I saw 

 there was not a single exception. On starting to walk down to the 

 Heuthal, but still on the top of the pass, and overlooking that 

 astounding contrast of lakelets the Lej Alv and the Lej Ner, I came 

 across several other species ; Erebia i/orne, (always of the var, triopes, 

 showing that this really was the eastern alpine region at last), E. 

 lappnna and E. tyndarus were common, Brentkis pales was not scarce, 

 there were a few Pontia callidice and Melitaea varia, and I took one 

 example of each sex of M. ci/nt/tia, the 3' being a very handsome 

 aberration in which the white extends to the base of the forewing, 

 broken only by a large round black spot, the hindwing also showing 

 much more than its due proportion of white. I saw but little as I 

 walked down to the Heuthal, and butterflies even there, though fairly 

 abundant, were by no means in such profusion as I have seen them 

 there later in the month. B. pales, and more especially the isis form 

 with the ? napaea, was as usual extremely common, Cyaniris seiiii- 

 aryiis, Albnlina pheretes, Melitaea vierope, Coenonyinpha satyrion var. 

 vnicolor and Erebia tyndarus were by no means scarce, Latiorina 

 orbitnlns and Melitaea varia appeared, but no doubt became much 

 commoner later, Parnassins delins and Pontia callidice were decidedly 

 scarce, and there was a profusion of black-and-white skippers, those 

 netted consisting almost entirely of Hesperia cacaliae and H. serratnlae, 

 but giving one example which I think may be safely regarded as the 

 mountain form of H. alvens. I had expected on approaching the 

 Bernina-Haus station to have found Erebia pharte again, but the 

 railway has considerably altered the aspect of the ground and there 

 was not time to hunt for its old locality under changed conditions. 



