216 Dr. Fritz Muller's Notes on 



of the wing. If we knew only these- two species of 

 Nymphalina and Satyrince, we should unhesitatingly 

 assume that their odoriferous organs, situated on the 

 same place, composed of the same parts, and in the same 

 position, were inherited from common progenitors ; and 

 yet this would be a great mistake. 



B. Ageronia group. 



lu the male of Ageronia Arethnsa a rather strong 

 odour is emitted by two large brown spots, situated 

 between the Avings, one on the under side of the front 

 wing, occupying the basal half of the cell between the 

 submedian nervure and first median nervule, the other 

 on the upper side of the hind Avings. The microscopical 

 structure of the scales and the wing-membrane of tliese 

 spots diifers but little from that of the rest of the wrings. 

 In Ageronia Amphinome and Feronia neither odours 

 nor odoriferous organs could be detected. 



Didonis Biblis is, so far as odours are concerned, the 

 most interesting of all butterflies that I know. The male 

 is able to emit as many as three different odoiu's. On 

 seizing a Didonis of either sex, it proti'udes on the dorsal 

 side of the abdomen, between the fourth and fifth seg- 

 ments, a ]mir of hemispherical protuberances, covered 

 with greyish hair-like scales and producing a strong, 

 rather disagreeable odour. The male has a second pair 

 of similar protuberances between the fifth and sixth seg- 

 ments of the abdomen, covered with white hair- like scales. 

 These white protubei'ances he never exposes when caught ; 

 they emit an agreeable odour, comparable to that of 

 heliotrope, and are of so elegant an appearance that they 

 probably serve at the same time as an ornament. A very 

 different musk-like odour is produced by a black spot, 

 Avhich is situated on the under side of the front wings 

 of the male near the base between the median and sub- 

 median nervures. This odour is very faint; it is con- 

 venient to remove the abdomen before trying to perceive 

 it. I may add that the hind wings of the male also have 

 a very small greyish spot near the base, which is wanting 

 in the female. 



C. Apatura group. 



A distinct odour issues fi-om the tuft of black hairs 

 which distinguishes the hind wings of the male sex of 

 Prepona Tuiertes and several other allied species. 



