65 



Agriades thetis {hellargns) was not met with until September 5th, 

 on which day it was found very commonly in Cow Gap and had 

 evidently been on the wing for some days. To see this species at 

 its best one needs to be on the ground in the morning, as, soon 

 after mid-day the sun begins to lose its power on the banks fre- 

 quented by the butterflies, and early in the afternoon portions of 

 the ground are in shadow, and a thinning down in the numbers on 

 the wing is soon noticed, nor are the butterflies then to be found on 

 the grass stems, but seem to have a knack of secreting themselves 

 among the rooty parts of the thicker grass tufts and in all sorts of 

 inaccessible places on the steeper parts of the banks. From the 

 time when the species was first noted it steadily increased in num- 

 bers, and indeed appeared to be more abundant than in the past few 

 seasons, and no diminution in numbers was noted throughout Sep- 

 tember. During early October there was a decided thinning down, 

 but even then it was still to be found commonly, and many of the 

 individuals of both sexes were quite fresh. It was last seen on 

 October 17th, a beautifully fine, warm morning, when some three 

 or four dozen were noted, and among them two or three of the 

 males were brilliant in their freshness. Fine weather continued for 

 a few days longer, and no doubt the species remained on the wing 

 through them, possibly to the 20th or 21st, although the last that 

 I actually saw of it was on the 17th. Tutt, in his " Natural History 

 of the British Lepidoptera," devotes nearly four pages of closely 

 printed matter to the earliest and latest dates on which A. thetish&s 

 been found on the wing ; in these October is given only seven times, 

 and the 15th of that month is the latest date mentioned. It therefore 

 appears that even if the 17th, on which I saw it last autumn, was 

 the last day on which it was actually on the wing, it was an 

 exceptionally late date for the species. 



From the foregoing it will be noted that A. coridon and A. thetis 

 are flying together in this locality for two or three weeks, and have 

 every possible opportunity for cross-pairing, yet I have never seen 

 such an occurrence, nor have I ever come across any specimen that 

 suggested in any way the possibility of it being a hybrid. 



Before leaving the butterflies there is just one other point that I 

 should like to notice. Many years ago when I used, as a youngster, 

 to go to Eastbourne very occasionally for a day's collecting, a rough 

 cart track ran from the end of Meads Street, a hamlet about a 

 mile from the then western end of the town, across a cornfield and 

 down the side of an old chalk pit to the beach, and had evidently 

 been made for the purpose of serving a pair of limekilns, the foun- 

 dations of which were then still standing. On the left of this track 

 was a high grassy bank having an almost due south aspect, and this 

 bank, as long as I can remember, was a haunt of A. thetis. Some 

 thirty years ago the sloping front of the cliff between the town and 

 this rough track was converted into parades, and the sloping banks 

 between them planted with shrubs and flowers and kept in a state 



