Chap. VI. 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 Muras 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 



