ARICIA MEDON. 273 



front of this the head and pro thorax form a nearly hemispherical 

 projection, about 2-onim. high at lst-2nd thoracic incision. This is a 

 re-entrant angle, beyond which the mesothorax rises in a dome to 

 3-4mm. high, 2-5mm. from front, then after a slight hollow to 8mm. at 

 thoracic-abdominal incision, 3-8mm. from the front; it rises again to 

 about 3'2mm. along abdominal 2nd, 3rd, and 4th, and then curves down 

 to the end. Posteriorly from 3rd-4th incision 5'5mm. from front, the 

 ventral line leaves the surface of attachment, so that the apex is about 

 l'5mm. above it. There seems to be no trace of cremaster. April 17th. 

 — The fairly mature pupa is much as already described, the wings look 

 more solid, and the green is of a rather more olive hue, but the dark 

 marks remain on eyes and wing-base, and the pink dorsal and 

 lateral lines are still conspicuous. The hairs are rather more 

 numerous dorsally and laterally, i.e., along the lines of " flanges." 

 The pupa is of the usual Plebeiid form, 9'4mm. long in the specimen 

 observed, 3mm. at the widest portion (3rd or 4th abdominal segment), 

 tapering slightly forwards, more rapidly backwards, rounded at each 

 end. As in other Plebeiids, the posterior extremity behind the end of 

 the appendages is very short, about l*4mm. The pupa is one of the 

 most hairy of the Plebeiids, the hairs being at least as numerous as in 

 condon for example, and though the pupa is smaller, the hairs are of 

 much the same length, 0-1 5mm. The colour of the pupa shell is pale 

 terra-cotta, so that the colour of the living pupa is that of the contained 

 fluids till the imago matures. The glazed eyes are, however, nearly black, 

 and the maxillae and antennae are darker than the rest of the pupa. 

 As in various other Plebeiids, the ends of the maxillae dip into the 

 pocket behind the 5th abdominal segment to a depth of 0*8 or 09mm. 

 The cremastral area is entirely without hooks, but has (i.e., the 9th 

 and 10th segment have) some 16 ordinary hairs and 3 or 4 lenticles. 

 The hairs on the head, and those on the thorax and even the abdomen 

 are somewhat similarly circumstanced, and are each surrounded by a 

 small area into which the netted sculpturing does not encroach, giving a 

 very pretty and special effect ; this arrangement does not obtain, in 

 the Plebeiid pupae examined, to a sufficient degree to attract notice, 

 though it is universal, in pupae possessing them, for the lines of 

 sculpturing to avoid hairs and lenticles. The netted sculpturing is 

 much better appreciated in a photograph than by description. There 

 is a dorsal head-piece, each half of which (about 08mrn. long) remains 

 in dehiscence attached to the prothoracic margin, it is narrow and shuttle- 

 shaped. Theprothorax (each half about 2mm. x 1mm.) is well sculptured 

 and plentifully supplied with hairs and lenticles. The cover of the 

 first spiracle on margin of mesothorax (0*4mm. long) has the usual 

 appearance of a crowd (but a very orderly one) of minute hairs with 

 tabular tops. There is a dark shade across the wing origin, and at its 

 middle is a place to which the lines of netting converge, but fade out as 

 they reach it. The lenticles on the legs are few and minute, and are 

 detected with difficulty. There are large flights of lenticles round the 

 spiracles and a good many hairs, and some smaller points that are 

 rather numerous and look more like hair-bases than lenticles. 



Habits. — This species may be called the l/ zigzagger," for it darts 

 swiftly to and fro when on flight, showing first its grey underside and 

 then its black upperside, so that one can hardly follow it with the eye. 



