42 Mr. J. O. Westwood on a greganom 



removed on denuding the wings of their scales, when their surface 

 was discovered to be entirely covered with an innumerable series of 

 minute wrinkles, giving the wing an elasticity which enabled me to 

 stretch them to nearly double their size on moistening them with 

 water: they immediately, however, returned to their former size on 

 withdrawing the hand. If we imagine the scales to be placed upon 

 the upper edge of each ridge, and that they increase in size as the 

 wings expand, we shall be furnished with a further clue to the 

 solution of the interesting question of the mode of the expansion of 

 the wings in this interesting order of insects. 



The antennse were found to terminate in a gradually elongated 

 club, which from the dried state of the specimens had sunk on one 

 side as represented in my figure. 



The palpi are rather longer than the head, distinctly three- 

 jointed, the third joint being as long as, but slenderer than the second 

 joint. 



From the interesting discoveries of Dr.Horsfield,the structure of the 

 legs however proved of the highest interest, the anterior pair being 

 eminently perfect, the coxae nearly as long as, and the tibise shorter 

 than the femora. The tarsi in the fore legs of all the specimens 

 which I examined were rather longer than the femora, distinctly tive- 

 jointed, vidth a large fleshy pulvillus, a pair of strong bifid claws, and 

 a pair of elongated membranous appendages. The middle legs were 

 rather larger, of a 2)recisely similar structure, except that the coxag 

 were not free but united to the mesosternum, Avhence this pair of 

 legs cannot possess such extensive pov^ers of locomotion as the ante- 

 rior legs. The hind legs were also similar, but somewhat shorter and 

 more slender. 



The body in a mutilated specimen which had arrived at the imago 

 state, but was unable to escape fi'om the nest, was about 4 inch long, 

 and an upper wing wliich I also found in a mutilated state was about 

 1^ inch from the base to the extremity, whence we may calculate 

 the expanse of the wings at about 24- inches. 



This butterfly, however, is equally interesting in another point of 

 view. Respecting its situation in the series of diurnal Lepidoptera, it is 

 to be observed, that from the mode of suspension of the chrysalis 

 and its smooth exterior, united to the structure of the butterfly, and 

 especially that of the fore legs, it will neither enter into any of the 

 present genera, nor even into any of the great divisions established 

 amongst butterflies. 



Latreille, in the new edition of the 'Regne Animal' (tom. v. p. 375), 

 lays it down as a rule that those butterflies which have the chrysalides 

 suspended vertically, and simply attached by the extremity of the 



