BUTTERFLIES 



467 



of the most richly-coloured species of this tribe have been 

 received in Europe, owe the most ornamental part of 

 their insect population to the absence of strong and 

 regular winds. Nineteen of the most handsome genera 

 of Ega, containing altogether about 100 species, are either 

 entirely absent or very sparingly represented on the 

 Lower Amazons within reach of the trade winds. The 

 range of these nineteen genera is affected by a curiously 

 complicated set of circumstances. In all the species of 

 which they are composed, the males are more than 100 

 to one more numerous than the females, and being very 

 richly coloured, whilst the females are of dull hues, they 

 spend their lives in sporting about in the sunlight, im- 

 bibing the moisture which constitutes their food, from 

 the mud on the shores of streams, their spouses remaining 

 hid in the shades of the forest. The very existence of 

 these species depends on the facilities which their males 

 have for indulgence in the pleasures of this sunshiny life. 

 The greatest obstacle to this is the prevalence of strong 

 winds, which not only dries rapidly all moisture in open 

 places, but prevents the richly-attired dandies from 

 flying daily to their feeding-places. I noticed this parti- 

 cularly whilst residing at Santarem, where the moist 

 margins of water, localities which on the Upper Amazons 

 swarm with these insects, were nearly destitute of them ; 

 and at Villa Nova (where a small number exists) I have 

 watched them buffeting with the strong winds at the 

 commencement of the dry season, and, as the dryness 

 increased, disappearing from the locality. On ascending 

 the Tapajos to the calm and sultry banks of the Cupar 1, 

 a great number of these insects re-appeared, most of them 

 being the same as those found on the Upper Amazons, 

 thus showing clearly that their existence in the district 

 depended on the absence of winds. 



Before proceeding to describe the ants, a few remarks 

 may be made on the singular cases and cocoons woven 

 by the caterpillars of certain moths found at Ega. The 

 first that may be mentioned, is one of the most beautiful 

 examples of insect workmanship I ever saw. It is a 

 cocoon, about the size of a sparrow's egg, woven by a 

 caterpillar in broad meshes of either buff or rose-coloured 

 silk, and is frequently seen in the narrow alleys of the 

 forest, suspended from the extreme tip of an outstanding 

 leaf by a strong silken thread five or six inches in length. 



