NEW SPECIES OF BUTTERFLY 483 



white ants. The floor was the bare earth, dirty and 

 damp ; the wretched chamber was darkened by a sheet 

 of cahco being stretched over the windows, a plan adopted 

 here to keep out the Pium-flies, which float about in all 

 shady places like thin clouds of smoke, rendering all re- 

 pose impossible in the daytime wherever they can eflect 

 an entrance. My baggage was soon landed, and before 

 the steamer departed I had taken gun, insect-net, and 

 game-bag, to make a preliminary exploration of my new 

 locality. 



I remained here nineteen days, and, considering the 

 shortness of the time, made a very good collection of 

 monkeys, birds, and insects. A considerable number of 

 the species (especially of insects) were different from 

 those of the four other stations, which I examined on 

 the south side of the Solimoens, and as many of these 

 were * representative forms ' ^ of others found on the 

 opposite banks of the broad river, I concluded that 

 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 singu- 

 larly 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-civilized Indians of 



^ Species or races which take the place of other allied species 

 or races. 



