IQ2 LLOYDS NATURAL HISTORY. 



for their beauty and their rarity, the latter being due to the 

 difficulty of obtaining them, even in the distant countries where 

 they are found. 



Among the largest and most conspicuous of the Tropical 

 American Butterflies are those belonging to the genus Prepona^ 

 Boisduval. They are very robust insects, measuring four 

 inches across the wings, which are broad and dentated, with 

 the tip of the fore-wings much produced, but not falcate, the 

 hind-margin being oblique and then nearly straight below; 

 near the inner-margin of the hind-wings of the males stands 

 a yellow tuft of stiff hair, as in Agrias. The wings are black, 

 and are generally crossed by a broad blue or greenish-blue 

 band, often interrupted below the costa of the fore-wings. In 

 some species the whole of the wings is suffused with rich 

 purple ; in others the blue band is confined to the hind-wings, 

 and is reduced to a blue blotch. The most beautiful species is 

 P. praneste, Hewitson, from New Granada, which might easily 

 be mistaken for an Agrias, but for the much broader fore-wings 

 with the hind-margin concave. It is black, suffused with rich 

 purple, and with a sub-marginal row of scarlet spots. From the 

 base of the fore-wings runs a scarlet band, narrowly continued 

 along the costa for three-fourths of its length, but, beyond the 

 cell, continued in a broad curve to the band of spots at a point 

 opposite the middle of the hind-margin. On the under side 

 the Prepona are varied with different shades of brown and 

 grey ; sometimes there is a transverse black or white line, and 

 very frequently a 'number of short irregular zig-zag lines 

 towards the base. On the hind-wings beneath there is either 

 a sub-marginal row of small eyes between the nervures, or two 

 larger eyes, one towards the tip, and the other towards the 

 anal angle; the latter is sometimes visible above. The 

 larva and pupa resemble those of Apatura ; and notwith- 

 standing the strong and rapid flight of the Butterflies, they are 



