THREE WEEKS IN THE HIGHER PYRENEES. 57 



Gavarnie this year, the only one even approaching abundance 

 being A. exulans, on the opposite side of the Cirque at about 

 7000 ft. With these and a lonely example of A. contaminei my 

 three weeks' list is practically complete ! 



Arriving at the top of the zigzag the ground opens out some- 

 what with steep side slopes, terminating at the lower path level 

 with beech woods and occasional firs. The numerous flocks 

 and herds hereabouts had grazed the pasture thin, but still 

 there were plenty of wild flowers and stubby conifers to attract 

 the butterflies, it being noticeable, in this connection, that 

 Plebeius argus, which was flying in hundreds, preferred the shrubs 

 to the plants when at rest. A few days later, on the same 

 ground, the females of this dainty " Blue " had almost entirely 

 superseded the males, and were equally abundant. Of the 

 latter I took one or two, and examined a great many for 

 aberrations, but beyond occasional examples with the orange 

 marginal lunules of the upper side obsolete, I found little worthy 

 of remark. Mr. Lowe (Brit. Butterflies, Tutt, vol. iii. p. 182) 

 notes this form in Guernsey apparently — " entirely fuscous " — 

 but I am not familiar with it elsewhere, and it is curious that 

 Tutt, who was singularly fertile of names, did not (I think) 

 consider it worthy of a special designation. While I am on 

 this subject, I may also mention that the Gavarnie form of 

 Agriades corydon is quite characteristic, and M. Oberthiir in 

 the first instance drew my attention to an almost constant 

 variation of the under side of the male. On the fore wings, 

 which are silvery white, no markings of any sort remain except 

 the discoidal spot and the antemarginal sickle-shaped row, 

 which is composed of abnormally small and sharply defined 

 spots. The hind wings are of the same colour as the fore wings ; 

 the marginal spots survive, but the marginal thin line and the 

 orange lunules are almost imperceptible. The bases are powdered 

 silvery blue ; the basal, costal, and antemarginal spots all with- 

 out ocellation, and very small. Indeed, were it not for the 

 remaining black spots on the marginal row of the hind wings, 

 the whole facies bears a strong resemblance to the under side of 

 Poli/ommatus meleager, male. Corydon was just coming out 

 when we arrived ; it was afterwards plentiful locally. The 

 females showed no tendency to blue suffusion, as was also the 

 case with those of P. argus, but I took one of the pretty form 

 on which all four " discoidals " are strongly edged with white 

 (= ab. albicincta, Tutt). A rather striking peculiarity of the 

 " Blues " this year in the Central Pyrenees was what might be 

 called their emergence by instalments, and it happened both 

 with corydon, and more markedly with P. pyrenaica, that just 

 when the males appeared to be on the wane there would come 

 (often in the same localities) a fresh supply to take the places of 

 the forwards. 



