CYANIRIS SEMIARGUS. 289 



studded with shining black raised processes and tiny white hairs; 

 scattered over the body are shining black spiracular-like discs, very 

 small, common to the Lycamid larva?. On the 7th abdominal segment 

 is a transverse gland, very like that on the same segment of 

 Lrjcaena avion larva, but in C. semiargus (ads) it is not fringed with 

 extremely minute branching hairs, but is, instead, surrounded by 

 numerous little circular discs and tiny white simple hairs; and 

 on each side of the 8th abdominal segment is a retractile whitish 

 tubercle; the claspers and ventral surface are glaucous; the legs 

 whitish, ringed with dark olive (Frohawk). See also Brabant 

 {Bull. Sac. Ent. France, 1896, p. 260). 



Larva. — First instar : When hatched barely 100mm. Ion?, and 

 at most l-8ram. when full-grown, and with head stretched to full 

 length of " neck." The head is black, or nearly so, and the rest of 

 the larva a pale ochreous ; "colourless," though not correct, would, 

 perhaps, nevertheless, convey a more adequate idea of the uniformity 

 of tint, and want of colour, suggesting very strongly an internal 

 feeder, which in truth it is during the first instar; the hairs are colour- 

 less, but their points of origin are dark like the head, but so small as to 

 require a good deal of magnification to become visible. The general 

 arrangement of hairs, lenticles, etc., is the same as that described in 

 Plebeian argus (aegon), and as obtains throughout the Plebeiids. The 

 seta on tubercle i is, on the 3rd and following abdominal segments, 

 about 0.2mm. long, the largest nearly 0-3mm. ; that on ii is a very 

 faint, hardly visible, hair, not more than half as long ; on the forward 

 segments these hairs are shorter. On the mesothorax one of the four 

 (usual) flange-hairs is replaced by a minute lenticle, strongly suggesting 

 a spiracle ; this is usual, but not invariable, four" hairs being sometimes 

 present. The two minute hairs (iii ?) between the lenticles and spiracles 

 are hardly clubbed, but retain the same thickness throughout their 

 length ; the front one is about - 024mm. long, the posterior about half 

 this. The prothoracic plate has the four usual long hairs, two short 

 ones near the front angle, and the two lenticles are large, the special 

 hairs at outer angles are more like ordinary hairs than they are later ; this 

 is usual in the first instar of other species. The dorsal hairs and lenticles 

 on the 6th, 7th, and 8th abdominal segments are all quite separate, not 

 fused as they are, or appear to be, where they are largely developed, as 

 in Plebeius argus (aegon). The prolegs have, on each pad, one hook 

 and a chitinous point representing another ; this second hook is some- 

 times a hook, sometimes only a point on the claspers. Second instar: 

 2-0mm. long when half -fed, and not specially stretched ; head black ; 

 true legs dark tinted; hair-bases black, and more numerous than in 

 first skin; skin-colour itself still somewhat uniform, but fuscous rather 

 than ochreous as in previous instar — fuscous, however, must be 

 understood as varying from white or colourless in that direction, and 

 not by any means otherwise than very pale. By July 25th, 1907, the 

 larva was full-grown in the second instar, of a greenish-grey ground 

 colour, with rather bright red, dorsal, subdorsal, and double lateral 

 lines; the subdorsal line consists of slightly oblique lines on each seg- 

 ment, but so that that on the following segment begins just above that 

 on the preceding. Head very small, black; prothoracic plate depressed, 

 faintly browner than the ground colour ; the upper lateral line in the 

 marginal flange, the lower, the true (?) marginal, or lower lateral, flange 



