204 BRITISH BUTTERFLIES. 



intermediate iD length between those of A. thetis and A. coridon, but 

 are decidedly sharp-pointed ; most of them have comparatively sharp 

 points, in the other species they are almost without exception thick and 

 rounded at the ends, least so in A. coridon. The cremastral area, 

 though without hooks, has a few ordinary hairs and some rosettes. 

 There is present a small dorsal headpiece, spindle-shaped (about 

 0'8mm. x0 - 2mm., portion of one side), attached to the anterior 

 margin of the prothoracic piece. ' This piece is so liable to be lost 

 that failure to see it must not be taken to imply its absence in other 

 species, it is probably present in the pupas of all these Plebeiids. In 

 a mounted pupa of A. coridon the dorsal pieces are attached to the 

 face head -pieces (see pi. viii), in my mounted specimens of A. thetis it is 

 wanting, but it is easily seen in some undamaged pupa-cases. Across 

 the front -of the abdominal segments rosettes are fairly plentiful, but on 

 each side, where hairs are fairly abundant in A. coridon, they are here 

 very few (Chapman). 



Habits. — Possibly the best-known " blue " in the British Isles, the 

 habits of Polyommatus icarus have been under the notice of numberless 

 races of lepidopterists, and its excited rifling of flowers of thyme, 

 marjoram, clover, and other nectar-bearing plants, its general restless- 

 ness, its pugnacious chase of butterflies larger than itself, its habit of 

 sitting on flowers in the hot sun and moving its hindwings wheel-like 

 in evident enjoyment, and its lazy indifference on a warm hazy day, 

 when the sun's rays find difficulty in filtering through the fine mist, 

 and it rests with its wings not pulled forward nor flattened horizontally 

 as in full glare, but opened sluggishly rather less than halfway, must 

 be known to everybody. That the $ s usually emerge a few days 

 earlier than the ? s has been often recorded, not only in Britain, but 

 from the Mediterranean, area. The pairing-habit of the species, as we 

 have observed it, is characteristic of the genus, the $ attracted to a 

 newly-emerged $ pairs without much trouble. Wilkinson's observa- 

 tion (Ent. Bee, xix., p. 240) is the opposite of ours, for he observes 

 that the 2 > when calling, seems to be very restless, and that on no 

 occasion did a $ copulate till after several attempts and after much 

 fidgetting and flying of the ? , whilst, on one occasion, he noticed the 

 pairing take place during flight, a flying 2 being joined by four $ s, 

 one of which united with her when about a yard above the ground. 

 Our own experience has been somewhat different, and, as a rule, we 

 have observed the $ to be rather lethargic when a $ has paired with 

 her, crawling a little if disturbed, but not taking wing. It is remark- 

 able, however, that, after they are paired, the $ , whilst on the ground, 

 appears to be at the mercy of the 2 , who moves sometimes a considerable 

 distance before she finds a suitable place for resting when she has been 

 disturbed, and drags the <f after her, but if made to take flight the 

 tables are turned, and it is the £ that carries the 2 . When paired 

 and at rest in a vertical position, the $ almost always rests upper- 

 most. Pairing usually takes place in the morning, and the pairs 

 remain in copulation some time, being quite conspicuous at the end of 

 the afternoon near the tops of grass culms, knapweed stems, or other 

 upstanding plants. Smallman notes a pair first observed about 4 p.m. 

 on June 8th, 1907, at Eastbourne, which remained in cop. till 8 a.m. 

 the following morning. Jenner-Weir records (Proc. Sth. Lend. Ent. 

 Soc, 1892, p. 92) that he once took a $ A. thetis paired with a 2 P. 



