66 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
tinctly striated pebble, a compound quartz-bearing rock, with one 
well-rounded side and a surface of more recent fracture. The 
rounded surface bore striae. The pebbles in this conglomerate are 
Compact blue pess] 
oe a : 
Louassik Plats 
Fria. 16.— Section of the conglomerate and overlying sandstones at Serrinha, 
Paran4, in the gorge of the Iguasst. 
rather closely scattered through a matrix of abundant sandstone of an 
argillaceous character, suggesting the deposition of the mass by float- 
ing ice. 
The whitish sandstone overlying this conglomerate is so like that 
forming the base of the Devonian northward in the Serrinha ridge 
that the question is raised whether this conglomerate belongs to the 
Permo-Carboniferous series or to the Devonian. ‘There is no appear- 
ance of faulting in the neighboring district which I discerned. The 
Devonian shales which separate the Devonian sandstone from the 
basal Permian at Ponta Grossa on the north have at this distance on 
the south disappeared, and it is possible that the Sandstone has also; 
the Permian by overlap coming close down to if not in contact with 
the Pre-Devonian east and north of Serrinha, the local resemblance 
of the white sandstone to the typical Devonian being assignable to a 
redeposition of those sandstones. The determination of the Devonian 
age of the lower beds at Serrinha, should it be made, would introduce 
another glacial epoch in south Brazil parallel to the case in South 
Africa. In this report I have preferred to follow the tentative opinion 
of Dr. Derby that the Serrinha section is Carboniferous (Permian). 
This view involves at least two advances of the ice in Permian time. 
The Section at Lapa.— Lapa is a station on the railway south of Ser- 
rinha. Along the line of railway southward from Serrinha after 
surmounting and crossing the sandstones on the south bank of the 
Iguassti the tillite beds are traversed by the train. Near and north of 
Pivary the campo surface is strewn with rounded stones. About 
