THREE WEEKS IN DAUPHINY. 283 



at Le Lauteret as Festucapumilosa — is the pabulum of the species. 

 This same female obliged with several eggs in the pill-box to 

 which she was consigned — a rather unusual occurrence in my 

 experience of this butterfly, and of the whole Erebias, though I 

 have known single eggs expressed from the body in the killing- 

 bottle. As at Larche, the La Grave alecto are without exception 

 of the form which M. Oberthiir has named daponcheli, and hardly 

 to be distinguished from the familiar var. at ab. pliUo of the 

 Central Alps. I am sure this insect is possessed of abnormal 

 hearing power ; when approaching, the displacement of the 

 smallest stone causes it to get up. Its method of flight is also 

 peculiar. I watched many males in their apparently aimless 

 and inconsequent zigzag flight over the moraine — like that of 

 Orgyia antiqua in a London square — suddenly flopping on a 

 stone, very seldom on a flower, and immediately orienting to the 

 sun with wide outspread wings. The females do not indulge 

 in these eccentricities. They keep low above the surface when on 

 the wing, and are naturally sluggish and slower than the males. 

 When the sun is overcast both sexes at once slip for shelter 

 under a stone, or into the crevices of rock, and neither, as 

 with some other Erebias, can be got to move when the sky is 

 cloudy. 



It is perhaps worth remark also that, if the tendency of 

 the grass Erebias is towards diminutive size at La Grave 

 and Le Lauteret, the ubiquitous stygne is rather larger than 

 otherwise. Where they present local variation, I make a point 

 each year of netting a few, but the aberration captured in the 

 gorge below the vacherie on the Meije path, about an hour's easy 

 walking from the village, came as a great surprise, and is the 

 most remarkable form of this common butterfly I have ever 

 encountered. It is an absolutely fresh male. The bands 

 on both wings appear to be better developed than usual, but 

 this, I think, is more apparent than real, and due to the entire 

 absence of the black spots in which ordinarily the white pupils 

 are set. The pupils themselves are reduced to mere metallic 

 pin-points. Unless already distinguished with a name, I propose 

 to call it ahannulata, new ab., and it would be interesting to hear 

 whether any of the many lepidopterists who have collected 

 E. stygne in France or elsewhere have met with a similar form. 

 Favre's ab. ahoculata female is described by Mr. Wheeler 

 ('Butterflies of Switzerland,' p. 132) as "without spots fore 

 wing, upper and under side ; hind wing, with two black dots in 

 place of eye-spots." In M. Oberthiir's figures of his var. 

 gavarnica, male ('L6pid. Comparee,' plate xxv., fasc. iii.), the 

 rusty bands on the upper side of the fore wings are much 

 narrower than in the type, the pupilled spots tiny (under side 

 one small apical spot only), and much closer to the outer margin; 

 the female showing the same peculiarities. 



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