POLYOMMATUS ICARUS. 



203 



nodulated points (rosettes). The reticulation is complete, i.e., the 

 lines do not end free, but are continuous as on the wings of Chatten- 

 denia iv-album. There are a good many dark minute lenticles near 

 the spiracles. The narrowness of the head, its forward position (not 

 having the prothorax as a cowl), contrasts markedly with C. w-album ; 

 the thorax and the abdomen are more nearly of the same width and 

 height than in, for example, Celastrina argiolus ; the width at the 

 wing-base is 3mm., at the 3rd abdominal, 4mm., so that the difference 

 is, nevertheless, considerable ; the mesothorax rises into a median ridge, 

 flattened on each side. The pupa for some days after changing is 

 very delicate and transparent. The thorax green, the head and 

 abdomen olive, the wings rather white when they lose their absolute 

 transparency. The dimensions of the pupa may be tabulated as 

 follows : 





FROM FRONT 





HEIGHT 



■ 



(along dorsum). 



WIDTH. 



(dorsum to venter). 



Front of prothorax 



04mm. 











Front of mesothorax 



l-0mm. 



2 -5mm. 



— 



Top of mesothorax 



l-8mm. 



3*4mm. 



3 -6mm. 



Posterior margin of mesothorax . 



2 -8mm. 



3*5mm. 



— 



Middle of metathorax 



3 # 6mm. 



3-6mm. 



— 



Front of 1st abdominal 



4 mm. 



— 



3"4mm. 



Front of 2nd abdominal 



4*4mm. 



— 



— 



Front of 3rd abdominal 



5'4mm. 



3-8mm. 



— 



Front of 4th abdominal 



6'4mm. 



— 



— 



Front of 5th abdominal 



7* 4mm. 



3-0mm. 



3-7mm. 



Front of 6th abdominal 



8*2mm. 



— 



— 



Front of 7th abdominal . . 



9 mm. 



— 



— 



Front of 8th abdominal 



9*5mm. 



l-6mm. 



— 



Front of 9th abdominal 



10 mm. 



— 



— 



End of pupa 



10'2mm. 



— 





(Chapman). The pupa is nearly cylindrical, though rather wider than 

 deep, rounded at the ends, 10mm. long and 4mm. wide across the ab- 

 domen ; the back of the thorax rises with a round curve, and drops a little 

 at the waist, the abdomen going in a curve to the tail ; the wing-cases 

 rounded, the pupa-skin, especially at the wing-cases, very delicate 

 and shining ; colour generally pale green, head pale brownish, 

 wing-cases with a very faint brown tinge, a dark green line down the 

 middle of the back of the abdomen, the spiracles whitish, a few short 

 bristles scattered on the skin (Hellins). The pupa is rounded at both 

 extremities, and is without angles ; the anal extremity is without the 

 usual minute hooks for attachment ; the region about the head is 

 furnished with minute bristles ; the colour is dull green ; the head, 

 extremity of wing-cases, and ventral surface of abdomen tinged with 

 brown (Newman, Ent., iii., p. 15). 



Comparison of pupa of Polyommatus icarus with pup.e of 

 Agriades thetis and A. coridon. — The pupa is very similar to that 

 of Agriades thetis or A. coridon, especially in the apparent want of 

 hairs and the absence of any cremastral hooks ; rosettes are also scarce. 

 It is easily distinguished by the character of the hairs ; this is most 

 marked in the prothorax, where the hairs, simple or slightly clubbed 

 on A. coridon and A. thetis, have here the club w T ell clothed w r ith com- 

 paratively long spicules ; the hairs round the spiracles are somew 7 hat 



