78 



A YEAR OF COSTA RICAN NATURAL HISTORY 



had completely lengthened and brought even the bases of 

 the hairs into view the hairs were directed every way and the 

 brush became spherical. The brushes of right and left side 



were thrust out together, in our ex- 

 perience, and when fully expanded 

 gave an extreme width of about 24 

 millimeters or I inch to the appar- 

 atus at the tail end, which of course 

 was in striking contrast to the same 

 end when the brushes were with- 

 drawn. Each stalk was about the 

 same length as the last abdominal 

 ^^ segment and on its inner side was 

 a flesh-colored elongated tubercle 

 about half as long as the stalk. 

 Abdomen of butterfly, Lye- Each brush was composed of some 

 area atergatis, male, showing hundreds of hairs, each hair was 



brushes fully extended. Drawn ^^^^^ 5 millimeters long. Under 

 from life. Enlarged 1.7 times. , , . 11. 



the compound microscope the hairs 

 are pale yellow for a short distance at their bases and 

 entire in outline, but for most of its length the hair is 

 black, opaque, and its outline is saw-toothed. The teeth 

 are sharper as the tip of the hair is approached, and are 

 apparently little scale-like protuberances directed toward 

 the tip of the hair.^ 



Lycorea is a representative of the Danaine butterflies 

 (of which the Monarch or Milkweed butterfly is the best- 



^ In an African Danaine butterfly, Amauris psyttalea, Dr. G. D. H. Carpenter 

 made the observation that the male fluttered about four inches over the female's 

 head, quickly protruding the brush at the hind end of the abdomen and as quickly 

 drawing it in again and adds "it was impossible to doubt that the male was en- 

 deavouring to excite the female" {Proceedings, Ent. Soc, London, 1914, p. cxi). 

 Scent organs of male Danaine butterflies have recently been discussed by Dr. H. 

 Eltringham in the Transactions of the same Society for 1915, pp. 152-176, through 

 which further references to the literature on the subject may be obtained. 



