PLEBEIUS ARGUS. 223 



A specimen 9mm. long, is 3*3mm. across the 3rd abdominal segment, 

 and one 10mm. long, is 3*5mm., so that they are nearly three times as 

 long as broad. The 10mm. specimen, 2mm. from the front, is 2*9mm. 

 across the mesothorax, thence it increases to 3*5mm. at 6mm. from 

 the front, the margins between, as seen from dorsum, being quite 

 straight (the wings); thence it tapers without much curvature to 1mm. 

 quite close to the rounded anal end. Seen laterally, the undersurface 

 is very straight, a slight rounding upwards in the front 1mm. (head), 

 and a slight downward projection of the anal extremity. The dorsal 

 line rises to 3mm., at 2* 5 mm. from the front, hardly sinks to a waist 

 at 4mm., and then rises to 3*3mm. at 6mm. (highest and broadest 

 part of pupa, 3rd and 4th abdominal segments) ; thence the line 

 curves regularly down to the posterior end, the curve being the longer 

 by the last segment being, as already noticed, slightly bent ventrad. 

 The furthest back part of the pupa is the dorsal margin of the 9th 

 abdominal segment, the 10th abdominal being quite ventral. Though 

 there are hairs, the pupa looks quite smooth and hairless, even under 

 a hand lens. The colour is green, inclined to yellowish or olive on 

 the abdomen, where the deeper tissues, shining through, are apparently 

 yellowish, and the pupal skin itself has, in some specimens, a faint 

 brownish mottling; there is a darker dorsal line, apparently coloration, 

 not dorsal vessel. The wings paler, and very transparent, with 

 tracheae very visible. The appearance of the posterior end suggests 

 more investigation as to its real structure, these parts, in Lycaenid 

 pupae, having so far puzzled me. The appearance here is distinctly 

 as if the 10th abdominal segment were folded underneath, its end 

 reaching into the ventral aspect of the 8th abdominal. Such cremaster 

 as there is, is quite ventral, and on what seems to be the posterior 

 border of the dorsum of the 9th abdominal segment. There is a very 

 broad margin beyond " Poulton's line," and the wings encroach some- 

 what on the 5th abdominal segment (Chapman). The pupa measures 

 10mm. in length; smooth, without polish, the top of the head slightly 

 projecting, the thorax rounded, the abdomen plump, curving on the 

 back outwards and backwards towards the tip, which is hidden in the larval 

 skin ; the wing-cases prominent and long in proportion. It is of a dull 

 green tint, with a dark brown dorsal line of arrow-head marks (Buckler). 

 Another pupa is 8mm. in length. Dorsal mew: Widest across the 

 middle of the abdomen ; the head is rounded ; base of the wing is 

 slightly angular and prominent, the wing curving gently over the side 

 of the abdomen, and is rather swollen ; the abdomen is attenuated to 

 the anal extremity. Lateral view : Head rounded ; thorax rounded 

 and swollen, and nipped in behind ; the abdomen is swollen about the 

 middle, and curves to the anal segment, which is blunt, rounded, and 

 furnished with hooks; the wing is a little swollen near the apex. The 

 whole surface is smooth, but not very shining. The colour is pale 

 ochreous-green ; the abdomen is darker olive-green ; head and anal 

 segment only very slightly tinged with green ; the wing shades into 

 whitish at the apex, and is semitransparent ; spiracles brown ; a dull 

 brown mediodorsal streak traverses the abdomen, and terminates in a 

 dark spot on the 7th abdominal segment. (Description made when 

 twelve days old.) About three days before the emergence of the imago, 

 the pupa begins to deepen in colour, gradually changing to a dark 

 leaden-grey, and finally the wings assume the colouring of the imago, 



