Chap. YI. 
CAISHANA INDIANS. 
373 
there could have been no land connection between the 
two shores during, at least, the recent geological period. 
This conclusion is confirmed by the case of the Uakari 
monkeys, described in the last chapter. All these 
strongly modified local races of insects confined to one 
side of the Solimoens (like the Uakaris), are such as 
have not been able to cross a wide treeless space such as 
a river. The acquisition which pleased me most, in this 
place, was a new species of butterfly (a Catagramma), 
which has since been named C. excelsior, owing to its 
surpassing in size and beauty all the previously-known 
species of its singularly beautiful genus. The upper 
surface of the wings is of the richest blue, varying in 
shade with the play of light, and on each side is a broad 
curved stripe of an orange colour. It is a bold, flyer, 
and is not confined, as I afterwards found, to the 
northern side of the river, for I once saw a specimen 
amidst a number of richly-coloured butterflies, flying 
about the deck of the steamer when we were anchored 
off Fonte Boa, 200 miles lower down the river. 
With the exception of three mameluco families and 
a stray Portuguese trader, all the inhabitants of the 
village and neighbourhood are semi-civilised Indians of 
the Shumana and Passe tribes. The forests of the 
Tunantins, however, are inhabited by a tribe of wild- 
Indians called Caishanas, who resemble much, in their 
social condition and manners, the debased Mtiras of 
the Lower Amazons, and have, like them, shown no 
aptitude for civilised life in any shape. Their huts 
commence at the distance of an hour's walk from the 
village, along gloomy and narrow forest-paths. The 
