180 BRITISH BUTTERFLIES. 



consist of a silken web in which are spun together gnawed pieces of 

 grass, sand, etc. (Staudinger). The puparium consists of a strong 

 coarse network cocoon, formed among the grass close to the ground ; 

 the loose gnawed pieces of grass, woven with the fine stems and blades; 

 in this the larva pupates in July, the cremastral hooks being very 

 securely anchored to a pad of silk spun for the purpose at one end of 

 the cocoon, whilst the long hooked hairs of the head are also fastened 

 into the cocoon so that the pupa is securely anchored fore and 

 aft (Frohawk) ; the larva covers the inside of the puparium with 

 the white asbestos-like material from the larval pockets under the 

 7th and 8th abdominal segments, and the pupa is covered with this 

 material, undoubtedly derived from the walls of the cocoon when 

 moving about (Chapman) ; the pupa moves very quickly when touched, 

 and, occasionally, rises for some considerable time with the anterior 

 part standing up vertically. The pupal period lasts about four weeks 

 (Staudinger). The very slight silken puparia were found on the 

 Reading downs, spun up among the short herbage near, but not actually 

 upon, the ground (Hamm) ; these were noted by Barrett as forming 

 a rather strong but rough cocoon of white silk, with abundant open- 

 work, the surface garnished with short pieces of dry grass-blades and 

 bits of moss, between which the pupa is clearly visible ; the anal 

 segment of the latter has a large, triangular, brown, horny projection 

 covered with bristles, terminated by a small, straight, blackish spike 

 surrounded by slender, but very strong, hooked bristles, by which the 

 pupa holds its silken envelope with great tenacity. 



Pupa (described from empty pupal skin). — General description: 

 Light greyish-brown in tint, with darker (blackish) and lighter (greyish) 

 marblings over the head and thorax ; stout in build, about 20mm. 

 long and nearly 5mm. wide (mesothorax to 4th abdominal). Front 

 end rounded, no nose-horn, body tapers to anus almost like a Noctuid 

 pupa, i.e., at first slowly, then more rapidly; w T ings extend only to just 

 beyond middle of the 4^h abdominal segment ; the third pair of tarsi 

 project from beneath them to end of extended segment, but free from 

 it, supporting maxillae, which proceed as a free appendage to end of 

 the 6th abdominal segment wmen segments are contracted (to end of 

 the 5th only when extended) ; hairs present over surface (except appen- 

 dages), in four or five transverse rows on abdominal segments; the 

 hairs bristle-like, pale, about O'ISmm. long. Detailed deserijition : $ . 

 [In order to see the pupa clearly it was necessary to dissolve off the 

 white asbestos-like powder w T ith benzole.] The first thing that strikes 

 one is that the hairs are of a totally different character and arrange- 

 ment from those of the larva. The pupa is 19mm. long (if the 5th and 

 6th abdominals were not somewhat telescoped, the length would 

 probably be 20mm.). Neither nosehorn nor any frontal projection. It 

 is comparatively stout, and though, being dehisced, and, therefore, 

 distorted in various ways, so that some measurements are not possible, 

 it appears to be 4*7mm. across the 4th abdominal segment, and 

 apparently rather stouter in front ; from the 4th abdominal it tapers 

 very slightly at first, then more rapidly to the somewhat sharp 

 cremastral spine. In front the pupa is rounded. The convexity of 

 the glazed eyes is directed rather frontally than ventrally ; the head- 

 and eye-covers remain in one piece ; the antenna 3 , legs and maxilla? 

 separate from the head-piece. The dorsal head-piece is not discovered 

 with certainty, it is either wanting or lost in this specimen, at least, 



