20 bulletin: museum of comparative zoology. 



correspond with the Estrado nova shales of Dr. I. C. White, while the 

 beds of sandstone in the face of the escarpment reddish below and 

 light colored above correspond with his Rio do Rasto and Sao Bento 

 beds respectively. 



The trap crowned pass of the Serra do Espigao is separated from the 

 main mass of trap on the south by ravines parallel with the escarp- 

 ment, somewhat as in the annexed sketch of the profile. (Fig. 24, 

 p. 93). The summit where crossed by the trail gave an aneroid 

 reading of 3,950 feet. A new cross by the roadside at the southern 

 side of the first ravine marked the spot where but a few weeks previous 

 a Brazilian had been killed by the Bugres. Of these savages, howe\er, 

 we saw none nor were we molested. Our bugreiro left us at a point 

 near the cross and returned to his post at the base of the escarpment. 

 On passing the summit I noticed fresh ice crystal marks in a dried up 

 mud-puddle. We descended at once the south slope of the ridge, 

 passing the lower contact of the trap on the sandstones to an open 

 campo watered by the Lageado liso, a small stream so named, in 

 common with many in Brazil, from the flaggy beds in its channel and 

 banks. The tilted attitude of a band of beds in the \'alley of this 

 stream suggested faulting parallel with the escarpment, but I was not 

 able to determine by the elevation of the base of the trap on the 

 opposite side of the valley the occurrence of a displacement of this 

 plane of reference, though it was my impression that the trap in the 

 Serra do Espigao lay higher. From the Lageado liso the ascent is 

 gradual but steadily upward to the top of a broad tableland of trap 

 giving aneroid readings of 4,050 to 4,100 feet elevation some 6 kilo- 

 meters south of the Lageado liso. At 8.6 kilometers some farm 

 houses appeared about which were fields enclosed with stone fences. 

 We descended into the valley of Passa dois on the south and went into 

 camp. Numerous poles set upright in the ground showed that here 

 the pack-trains halt for the night. 



^■iugust 22nd. — There was a heavy frost last night. Between one 

 and two kilometers south of camp red sandstones crop out with a 

 northeast dip. Reaching the Rio Correntes at the noon halt, the 

 route continued on trap to the camp for night on a small stream, the 

 Rio das Pedras, near a farm house where were pigs and cattle in fields 

 enclosed with rail fences. 



The surface of the basalt traversed in this day's journey varied 

 much in the degree of decomposition. For long distances there was 

 good hard rock with a thin brownish crust of weathered products. 

 Between these stretches along the road the rock was weathered down 



