6 



RHOPALQCERA MALAYASA. 



Pttp^:. — The pupa of the above, and also of 7f. Wcstw., ft J&Tan species, is figured by Horsf. and 

 Moore, ibid., pi. it., figs. II a and 12, 



The genus Hestia in the east, like the genus Morpho of the western tropics, may be taken 

 aa exhibiting what has been described as "excess of wing area/' which, with the comparatively 

 small and Light body, is more productive of lofty rather than of swift flight. Pettigrew, wlo 

 has exhaustively treated on the mechanical properties of animal locomotion, has laid down 

 the postulate that " The wing area decreases as the size and weight of the volant animal 

 increases";* and the same author has not only shown a law of " weight necessary to flight/' 

 but also that when the body is light and the wings very ample when they are driven at a 

 comparatively low speed (both in insects and birds), " the reaction elicited by the ascent and 

 descent of the wing displaces the body to a marked extent, "f or, in other words, an enormous 

 expanse of wings or pinions readily explains an irregular flight on the "principle of recoil." 

 This principle applies to large- winged and light-bodied species of Hestia, who though of lofty, 

 are not of swift flight* Eigg describes a Penang species as * ( a slowly sailing object," which 

 I can corroborate from my own experience ; and Tennent, | writing of the Ceylon species, 

 speaks of its wings "that bend and undulate in the act of flight," by this sentence probably 

 referring to the course of the whole insect. § On the other hand, confining ourselves to the 

 East, the more robust-bodied PapiUonid® have, as Collingwood has truly remarked, " strength 

 of wing and straight headlong course." || This is particularly the case with the large and 

 heavy-bodied Ornitkoptene, of which 0. hrookeana may be taken as an example ; Wallace, its 

 discoverer, not only speaking of its swift flight, but Burbidgel stating that in that respect 

 its flight resembles that of a bird. 



Probably about sixteen species exist, although some of the described forme may prove 

 to be but varieties of other species. The area over which this genus is distributed includes 

 Continental India, Ceylon, Andaman Islands, Burma, Malay Peninsula, and extending also 

 throughout the Archipelago, including Papua. 



Only two species appear to he found in this fauna. Mr, Bigg remarks that 11 There are at 

 least three distinct sizes of 'Ghosts' in the Straits*" In this enumeration he evidently 

 includes the species of the following genus Ideopsis. 



The food-plants being unrecorded, no knowledge of the geographical distribution of the 

 same can be obtained* 



L Hestia lynceus. (Tab. L, tig, 2.) 



Pap. hjneeus, Drnry, 111. Ex. Ent., ii. t t. 7, fig. 1 (1778). 

 bin hfncfit, Godt. Euc. M&h., ix., p. 105, n. 2 (1810), 



Male and female. Wings semihyaline and more or less fuliginous; neuration fuscous. Anterior 

 wings ubove with the following hlack macular markings: — two contiguous snots above and a little before 

 centre of cell, and a sulnjuudmte costal .spot tit apex uf lirst subcostal net* vule i a large irregular spot about 



* 1 Animal Locomotion,' p. 1$2, f Ibul., p. 119. \ Nat. Ui&t. Ceylon, p. 426. 



§ Wallace speaks admiringly of a species of Eettia at Singapore, "sailing or rather floating along, and having, to my 

 eye, a far more striking anil majestic appearance than oven the MorpJiai of Brazil/' — 4 Zoologist,' lHZ4 t p. 4390* 

 || ' Rambles of a Naturalist,' p. 182. 1T * Gardens of the Sun,' p, 260. 



