244 



BRITISH BUTTERFLIES. 



cellular vein. The shading of these and of the spaces by the darker 

 lines is very regular and beautiful. Poulton's line is very distinct. 

 It arises somewhere about half-way along the inner margin, passes 

 along the hind margin, terminating at vein 8, perhaps visible a little 

 beyond this, in some specimens becoming costal. The space beyond 

 Poulton's line is about 025mm. wide at anal angle, about 0*5mm. at 

 vein 7, and (obliquely) from vein 8 to apex is about l'Omm. The 

 hindwing is a narrow slip, stopping rather suddenly just before the 

 spiracle of the 3rd abdominal. The abdominal spiracles are incon- 

 spicuous, they are raised on slight cones, but only reach the general 

 surface level as the cones arise from oval pits with vertical walls ; these 

 walls present a slender black line ; the pits are, however, practically 

 absent on the posterior segments. The following dimensions of the 

 pupa may prove interesting : — 



• 



Length from 



Transverse 



Antero- 





front. 



DlAM. 



posterior Diam. 



Where front curves into side 



0*3mm. 



2-5mm. 



lOmm. 





1-4 „ 



2-5 „ 



2-0 ,, 



Back ,, (1st spiracle) 



1'7 „ 



25 „ 



2-5 ,, 



Wing-spines 



2-0 ,, 



3-0 ,, 







Highest point of mesothorax 



2-5 „ 



%J u ? ? 



3-0 ,, 



Posterior margin of mesothorax 



4-0 „ 



3'3 ,, 



30 ,, 



,, ,, meta thorax 



4-4 „ 





3-2 ,, 



, , , , 3rd abdominal . . 



7-0 „ 



4'0 „ 



3-7 „ 



4th 



8-0 ,, 



3-2 „ 



3-1 „ 



5th 



8'9 „ 



— 



2-8 ,, 



, , , , 6th , , 



9-7 „ 



2-3 „ 



2-2 ,, 



7th 



10-5 „ 



— 



1-7 „ 



,, ,, 8th ,, 



11-1 ,, 



— 



i-o „ 



9th 



11-6 ,, 



0-7 „ 



0-6 ,, 



,, ,, 10th do. = total length 



12-5 ,, 



— 



— 



(Chapman). Length about 12mm. ; thick and stumpy in outline ; the 

 eyes prominent, the wing-cases well developed ; the w T hole skin rather 

 rough ; the middle of the head, the eyes, and the back, set with short 

 stiff hairs; the ground colour reddish-grey, the wing-cases pinkish-grey; 

 the abdomen tinged with brownish-red along the back ; on the centre 

 of the head, on the eyes, and on either side of the thorax above the 

 wing-cases, are some blackish -brown marks ; there are smaller marks 

 in pairs down the middle of the thorax, and there are transverse rows 

 of spots on the segments of the abdomen, the largest and darkest being- 

 next the wing-cases ; the hairs are light brownish-red ; the anterior 

 spiracle is black, the others of the grey ground colour, ringed with 

 black and placed within the largest dark blotches (Hellins). 



Time of appearance. — This species, in the British Isles, is single- 

 brooded, occurring in May and June, but may appear a little earlier 

 or later, according to the season. In the lowlands of Central Europe 

 it is generally reputed as double-brooded, but a study of certain 

 critical remarks on this subject leads one to suppose that, at the most, 

 the species is, like all those that feed up fairly rapidly in the summer, 

 and pupate as soon as fullfed, only partially double-brooded, a few 

 (or many) imagines appearing, in peculiarly suitable seasons, as a 

 second brood, their progeny having to reach the pupal stage before 

 winter is on them. Occasional late individuals may represent this 



