Across Nhambiquara Land 237 



honey-creeper. In Colombia Miller found the honey- 

 creepers habitually coming inside the houses and hotels at 

 meal-times, hopping about the table, and climbing into 

 the sugar-bowl. 



Along this part of our march there was much of what 

 at a hasty glance seemed to be volcanic rock ; but Oliveira 

 showed me that it was a kind of conglomerate, with bub- 

 bles or hollows in it, made of sand and iron-bearing earth. 

 He said it was a superficial quaternary deposit formed by 

 erosion from the cretaceous rocks, and that there were 

 here no tertiary deposits. He described the geological 

 structure of the lands through which we had passed as 

 follows: The pantanals were of pleistocene age. Along 

 the upper Sepotuba, in the region of the rapids, there 

 were sandstones, shales, and clays of permian age. The 

 rolling country east of this contained eruptive rocks — 

 a porphyritic diabase, with zeolite, quartz, and agate of 

 triassic age. With the chapadao of the Parecis plateau 

 we came to a land of sand and clay, dotted with lumps of 

 sandstone and pieces of petrified wood ; this, according to 

 Oliveira, is of mesozoic age, possibly cretaceous and sim- 

 iliar to the South African formation. There are geolo- 

 gists who consider it as of permian age. 



At Vilhena we were on a watershed which drained 

 into the Gy-Parana, which itself runs into the Madeira 

 nearly midway between its sources and its mouth. A 

 little farther along and northward we again came to 

 streams running ultimately into the Tapajos ; and between 

 them, and close to them, were streamlets which drained 

 into the Diivida and Ananas, whose courses and outlets 

 were unknown. This point is part of the divide between 



