HAIRSTREAKS. 



107 



point before the anal angle is slightly pro- 

 duced. On the upper side all the wings are 

 brownish black ; every part in the males, 

 except the margins, has a purple reflection ; 

 in the females this purple reflection is confined 

 to a patch occupying a portion only of the 

 fore wings, all the margins and the apical 

 area of the wing being destitute of the purple 



Under side. 



colour. The underside is delicate gray, in- 

 clining to drab, with a transver.-e white line 

 on all the wings ; that on the fore wings is 

 very straight, but imperfect, not reaching the 

 inner margin ; in the hind wings the first 

 costal half only is straight, the inner-marginal 

 half is twice bent, and assumes somewhat the 

 form of the letter W ; there is a bright orange 

 spot -at the anal angle of the hind wings, and 

 a circular black-pu pilled orange spot near the 

 anal angle and also near the hind margin : 

 the space between the white line and the 

 hind margin contains a double series of pale 

 smoke-coloured markings. 



LIFE HISTORY. The EGG is laid on the 

 twigs of the oak (Quercus robur] in July, and 

 remains in that state during the winter, 

 hatching in the spring, and the young cater- 

 pillar feeding on the oak-leaves ; the CATER- 

 PILLAR is full grown in June, and then closely 

 resembles that familiar shell, the Chiton, and 

 rests appressed to the surface of the leaf, just 

 as the Chiton to the surface of rock ; the head 

 is small and retractile : the incisions between 

 the segments of the body are very distinctly 

 marked, the posterior edge of one segment 

 slightly overlapping the anterior margin of 

 the next following segment ; the back is very 

 convex, and is intersected by a medio-dorsal 

 groove, which is narrow and distinct on the 

 middle segments, but becomes vague and 



wide towards both extremities; the lateral 

 margin of all the segments is thin and dilated, 

 and every part of the body is clothed with 

 fine scattered hairs, which become conspicuous 

 when the caterpillar is viewed in profile : the 

 colour is dull brownish green, sometimes 

 tinged with pink, and there is a medio- 

 dorsal series of pinkish arrow-heads, the two 

 moieties of which are separated near the head. 

 In captivity this caterpillar spins no cocoon, 

 nor does it fasten itself by any belt or anal 

 hooks as is the manner of its tribe, but retires 

 just below the surface of the earth, and then 

 turns to an obese unangled brown CHRYSALIS, 

 which emits minute hairs from the entire 

 surface of its body Newman. 



Obs. At p. 312 of the second volume of 

 the " Entomologist," Mr. S. A. Davis writes 

 thus: "Whilst collecting in July at West 

 Wickham, I shook a small sapling ash, and 

 observed several specimens of Thecla Quercus 

 fly from it, and almost immediately return 

 and settle again on the leaves, in most in- 

 stances upon the same identical leaf from 

 which they had been distuibed. Further 

 observations proved this to be the case with 

 most of the young ash-trees in the wood, and 

 I could have captured dozens had I been so 

 disposed. The same day I observed about 

 twenty specimens gambolling and settling 

 upon an ash tree near Beckenham, no oak 

 being near." This seems to suggest the idea 

 that the food of the caterpillar is not confined 

 to oak, but I have no proof that this is the 

 case. 



TIME OF APPEARANCE The egg through- 

 out the winter, the caterpillar in June, the 

 chrysalis in June, and the butterfly in July 

 and August. 



LOCALITIES. In Ireland Mr. Birchall found 

 it common in the counties Wicklow, Dublin, 

 and Kerry : it has not been observed in the 

 Isle of Man. Dr. Buchanan White remarks 

 that " it is a rarer species in Scotland and 

 Perthshire than the Green Hairstreak ; it 

 occurs in several places in the lowland part 

 of the county of Perth as far north as Dun- 

 keld : although found in Argyleshire, it does 

 noc seem to occur everywhere in the south of 



