EHOPALOCEEA. 27 



is at rest) is more or less protective, from its obscurity or its resem- 

 blance to the tints of the customary surroundings. 



In two genera of butterflies, viz., Acrcca of the Sub-Family Acrceince, 

 and Farnassius of the Sub-Family Papilioninm — which are very remote 

 from each other in almost every respect except their semi-transparent 

 wings — the females exhibit a very remarkable and quite peculiar 

 structure, in the form of a horny pouch or sac, attached to the under 

 side of the abdomen. In Acrma this appendage is on the penultimate 

 segment, and is of moderate size, being best developed in A. NeobuU 

 and A. Horta ; but in Pamassius it is much larger, and in P. Delius 

 is widely open posteriorly, and occupies the whole under side of the 

 abdomen. The use of this pouch — which is often detached and lost 

 during life — has not been satisfactorily determined. 



A curious difference between the sexes is presented in several genera 

 of Lycmnidce, — such as Eiimmus, Myrina, Deudorix, and Capys, — where 

 the palpi of the female are considerably longer than those of the male. 

 The same character is noted by Westwood (in Gen. Diurn. Zep.) as 

 occurring in three genera of Urycinidce, viz., Alesia, Nymphidium, and 

 Aricoris. 



It occasionally happens that the male and female characters are 

 combined in one and the same individual butterfly, and, where the 

 secondary sexual differences are very marked, the appearance of such 

 an example is very singular. Boisduval {S^i. Gen. Lep., i. p. 27) men- 

 tions eight species of which so-called " hermaphrodite " individuals had 

 been noticed by authors, and a good many other cases have been re- 

 corded. A recent instance in South Africa is that of a specimen ofLycmna 

 Telicanus (Var. pulchra, Murray), taken near Grahamstown by Mr. F. 

 Billinghurst, in which the wings of the right side are of the female 

 pattern and colouring, while the left-hand wings are of those of the male. 



5. Haunts and Habits. 



The dependence of Butterflies on vegetation (especially in their 

 caterpillar state), and their need of shelter from high winds, explain 

 how it is that they chiefly abound in wooded districts. Sunshine, a 

 still atmosphere, and flowers are the surroundings most favourable to 

 the great majority of them : in exposed spots, when the weather is 

 boisterous, nearly all species are helplessly driven before the gale, and 

 they speedily succumb to combined cold and rain. There exists, of 

 course, a large number of species found in open country, and many are 

 peculiar to such tracts (especially in mountain stations), but forest-clad 

 lands are incomparably richer. Only a few butterflies, however, inhabit 

 the depths of woods, the great gathering of them being on the out- 

 skirts, or where the forest is broken by open spots and the sunshine 

 has access. In South Africa, the richest collecting-ground is the 

 wooded coast of Kaffraria, Natal, and Zululand, and the country about 

 Delagoa Bay seems almost equally productive. 



