LEPIDOPTERA.—RHOPALOCERA. 333 
« The velvet nap which on his wings doth lie, 
The silken down with which his back is dight, 
His broad outstretched horns, his airy thighs, 
His glorious colours and his glistening eye.” 
The number of species of butterflies is very considerable. Latreille 
and Godart described not less than 1804 in the Encyclopédie Méthod., 
of which 237 are natives of Europe, and considerable additions have 
been made to the number. They vary greatly in size, the gigantic 
Indian Ornithopteri being at least nine or ten inches in expanse, 
whilst some of our little British blues are not an inch across the 
wings. In their colours they are also equally variable, for, being born 
to flutter in the brightest sunshine, they are (like all sun-loving 
animals) much more gaily coloured than their nocturnal brethren. 
Their flight is also as varied as that of the feathered tribes, and the 
skilful collector knows at a distance the flight of the different genera, 
and even occasionally that of particular species. The power of flight 
depends considerably on the robustness of the thorax and the strength 
of the wing veins ; thus some of the Nymphalidee are far more pow- 
erful fliers, even than the great Swallow-tailed butterflies : such, for 
instance, is especially the case with Charaxes Jason (Jasius auct.) ; 
others, as the Pontiz, fly with an undulating flight, whilst Apatura 
sails over the topmost branches of the oak and the 
“ swift Camilla 
Flies o’er the unbending corn, and skims along the main,” 
with such graceful elegance, that an old Aurelian is described by 
Mr. Haworth as going to the woods long after he was unable to follow 
it, and taking his seat on a stile “ for the sole purpose of feasting his 
eyes with her graceful evolutions.” The knowledge of the diversity 
in the flight of the different tribes is, as Lacordaire well observes, “le 
fruit d’une expérience toute personnelle, et ne peut guére se trans- 
mettre par de simples descriptions.” (Ann. Soc. Ent. de France, 
1833, p. 382.) This author has, however, published a long and 
very interesting account of the butterflies of French Guiana in the 
memoir here referred to, and particularly described the mode of 
flight, habitats, &c., of the various groups. The prevalence of par- 
ticular colours in certain groups has been above alluded to: thus 
amongst the Pierides it is either white or orange tipped with 
black ; in the Hipparchiz, dull brown; in Polyommatus, blue ; in Ly- 
cena, fulgid copper; the Nymphalide have their wings varied with 
