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, however, 
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 valley 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. 
August 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 
