name of Jason in preference to that of Fabricius. This butterfly may be regarded as 

 one of the most splendid of the Lepidoptera of Europe, to the southern portion of 

 which and to the northern shores of Africa it appears to be confined. The strength of 

 its general structure indicates great powers of flight, and we accordingly find that it is 

 able to sustain itself in the air with very little motion of the wings. The female dififers 

 from the male only by having the centre of the posterior wings adorned with small 

 blue spots on the upper side. There are two broods in the year, namely in June and 

 September, and, according to M. De Villiers, the insect emits a strong scent of musk. 

 The caterpillar is naked and thickened in the middle of the body ; the tail tapering 

 into two short points, the head is also armed with two conical erect horns. In this 

 respect, therefore, this insect very nearly approaches the genus Apatura, of which the 

 purple Emperor, Ap. Iris is the type, thus proving the advantages to be obtained, in 

 studying the natural relations of this difficult order of Annulosa, from an accurate ac- 

 quaintance with the structure and habits of the early stages of the insect. 



There are several species, having the same general form as the Jason, including 

 Athamas, pi. '2. fig. 3. 4 ; Eudoxus, vol. iii. pi. 33. f. 1. 4 ; Camulus, vol. iii. pi. 30. f. 1. 2. 

 Mr. Swainson has, accordingly, formed them into a distinct group, to which he has given 

 the name of Jasia, in pursuance with his customary, but scarcely correct plan, of raising 

 the specific name of the tpyical species into a generic name, and then giving a new specific 

 name to such type. M. Boisduval, rejecting this system of nomenclature, has more 

 recently proposed for the same group the name of Charaxes, which I have adopted. 



Amongst the species very nearly resembling Jason, is one sent from Africa* to Mr. 

 Drury by Mr. Smeathman, which, according to the observations of that traveller, published 

 by Drury, in the introduction to his third volume, flies in the heat of the day with amaz- 

 ing rapidity, and seldom descends within eight feet of the gi'ound. It glances from the 

 prominent branches of one tree to those of another, as swift as a swallow, and turns its 

 head about instantly to the glade, or path, and will not suffer any person to approach 

 within a striking distance of it, but darts away on the least motion of the body. If the 

 collector exert his patience it will at last become more familiar and careless, and is then 

 to be caught upon some particular branch, to which it will appear more attached than to 

 another. 



* The name of this African species lias not been recorded. The following additional observations by Mr. Smeatliman will be ser- 

 viceable in enabling us to obtain an idea of the treasures which, even yet, European entomologists may expect to receive from this but 

 little investigated quarter of the globe. " The whole country of Africa, within the tropics, is one immense forest, except where the 

 sandy plains are too unsettled to afford a proper footing for vegetation. Wherever any inhabitants settle, they make plantations by 

 cutting down the woods and burning them to fertilize the ground, and never sow two years together on the same spot, but let the 

 trees grow up again for two or three years, by way of fallow, before they attempt to get another crop from it. It is tliese spots, wliich 

 Smeathman calls recent plantations, which afford the gieatest variety of insects and the easiest obtained. In the second and third 

 year they become impassable to human feet." 



