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tion of the Permian glacial formations of southern Brazil, most atten- 
tion was devoted to these interesting and significant deposits. Thick 
deposits of tillite were found quite extensively in the state of Paranda and 
in the adjacent portions of Sao Paulo and Santa Catharina. No gla- 
ciated rock floor, however, has yet been found in south Brazil, nor have 
the larger bowlders been found to bear striated surfaces, but the mem- 
bers of the expedition found ice-worn surfaces on pebbles and on frag- 
ments of rock ranging up to the size of a man’s head. Distinctly 
striated pebbles had not been discovered previously in these deposits. 
While maintaining a position of reserve, Woodworth believes that the 
gorge of the Iguassu at the point where the railway crosses it at Serrinha 
Station affords evidence of two glacial epochs within the Permian. 
The author refers to the hypothetical Gondwana-land and inquires 
whether it included Parana-land. In particular he raises the question 
whether there was a land connection between South America and Africa 
in Permo-Carboniferous times. He follows Suess in thinking that the 
Atlantic Ocean basin may have had its origin in post-Triassic times! 
He says: “Certainly the assumption of an Atlantic trough in pre- 
Triassic times having anything like the present extent of the basin must 
be abandoned as being without sufficient geological evidence.” He 
ends by saying: ‘‘We may conclude therefore that the geologist is free 
to converge the coasts of Africa and South America in Permian and 
earlier Carboniferous time as closely as any biological facts and geologi- 
cal evidences of land may demand for their explanation.”’ 
No doubt the great name Suess may warrant the taking of such 
convenient liberties with masses of continental dimensions, but to one 
who has toiled for a year or so on the ancient crustal wrinkles that face 
the South Atlantic it sounds like an excerpt from the Romance of 
Cataclysm. 
As a possible aid to genetic hypotheses of low latitude glaciation 
the author cites at length from authorities to show the frequency and 
effectiveness of hailstorms in warm countries and elsewhere, and seems 
to lean toward an explanation of Permian glaciation along this line. 
He would perhaps have added to the value of his contribution if he had 
drawn a sharper line between hot-weather hailstorms that spring from 
violent columnar convection and which drop their ice product in the 
hot bed that gave them origin, on the one hand, and, on the other, the 
common case of frozen rain and sleet that form when the conditions are 
on the wavering line between freezing and not freezing. The former 
have the merit of giving an impressive demonstration of the nearness 
