PLEBEIUS ARGUS. 225 



The angle that is really the hindwing, extends almost to the 3rd 

 abdominal segment ; it is marked off by a faint line or fold. The 1st 

 abdominal segment shows the usual network of lines, and also exhibits 

 well the finer network between them that marks, or is at any rate, of 

 the order of dimensions of, the cells that carry skin -points (the usual 

 spiculate ones, not those so-called here for convenience) ; there are 

 tw r o or three skin-points at either side ; it is about 2-Bmm. across, and 

 0-48mm. long dorsally. The 2nd abdominal segment is about 3mm. 

 across, and 1mm. long; it possesses a flight of lenticles above the 

 spiracle, with tw 7 o or three hairs, and skin-points (rosettes) are well- 

 developed. There are practically no hairs or lenticles except just 

 round, chiefly behind, the spiracles ; they are much the same on each 

 of the abdominal segments (2nd to 7th), with the following variations. 

 The lenticles are about 20 round each spiracle, but about 30 on the 

 6th abdominal, and only one or two on the 7th abdominal ; they are 

 largest on the 5th and 6th abdominals ; they have a wide, structure- 

 less, slightly-tinted margin, and a colourless lumen finely granular ; 

 the largest have a diameter of about 0-025mm. The hairs are three 

 or four near each spiracle, of the globular spiculate pattern, about 

 0-02mm. to 0*03mm. long ; on the 6th abdominal segment are several 

 larger ones; in one specimen there are two very globular, pear-shaped, 

 except that the base is very thick, and several others ; these large 

 ones are some 0*05mm. long ; on another specimen the hairs on this 

 segment are even more developed, several pear-shaped ones nearly as 

 large as those just noted, and two long baton-shaped, nearly 0*1 mm. 

 long, and only slightly swollen towards the ends ; the 7th segment 

 has five hairs round the spiracle on the first-mentioned specimen, 

 more on the second. There is, therefore, obviously, much variation in 

 the size and number of these hairs in different individuals. The 

 spiracles are oval, about 0-8mm. long, with about 25 lines radiating 

 from the centre, dividing the area into darker and lighter strips, 

 which, in some points of view, look something like ropes, each having 

 some diagonal lines, passing from the centre to the circumference. 

 The 8th segment has merely a spiracular scar w r ith one or two 

 lenticles, and three or four hair-bases, but no hairs beyond an obsolete 

 point. To discriminate between the 9th and 10th abdominal segments, 

 presents the usual difficulties common to Lycaenids. Centrally, is a 

 cremastral area carrying some 50 hooks ; this is partially marked off 

 by a (sutural ?) line from what is the dorsum of the 9th segment ; 

 ventral to it is another transverse suture, and, in front of this, an area 

 with three cremastral hooks on each side of its front margin ; these 

 are w r anting in one specimen (^ ). The anterior ventral margin of 

 the 9th segment carries a small angular projection in the middle of a 

 rather more chitinised margin ; in one specimen this projection is 

 about 0-lmm. wide, and terminates in a right angle, its surface being 

 covered with very minute acicular skin-points ; in another it is 

 # 3mm. wide, and has a curved margin ; this angular projection is 

 internal, not external ; fine acicular skin-points occur also on other 

 portions of this segment. It remains to deal with the face-piece and 

 appendage-cases. The face- (ventral head-) piece, though somewhat 

 angular, nevertheless fills a roughly circular area of about 2-Omm. in 

 diameter, with hollows scooped out for the bases of the antennae. The 

 mandibles meet in the middle line for about 0-25mm. ; above this line 



