340 Bevietv of Recent Geological Literature. 
as has been previously noticed in England. Tlirougliout Europe tlie 
marked change of the flora goes hand in hand with the change of climatic 
relations. As to the evidences of such glaciation in North America, Dr . 
Waagen is not assured; though he maintains tlie probability of a great de- 
pression of temperature occurring in the Permian. 
The glacial formations in the Hawksbury strata of Australia he regards 
as synchronous with the northern Permian glaciation and representing 
the diminished climatic severity and the recession of glaciation to the 
south. In India he finds no trace of Permian glaciation. The Permian 
fauna he considers to be not autochthonous, but of a composite origin, the 
greater part immigrating from China whither it had previously come from 
America at the age of the upper coal-measures. Another small tributary 
indicates a connection with tlift Carboniferous fauna of Aiistralia which, 
being imbedded in the glacial strata, may be considered as cold water 
fauna; and from this it appears why so few types, so many representatives 
of which occur in the Salt Range, have survived in the Permian of India. 
A third very small tributary indicates, finally, an origin in the Caucasus. 
In answer to the question why the glacial phenomena which destroyed 
Paleozoic plant types should not have had a similar effect upon the marine 
fauna and so caused the reduction of the Paleozoic animal types. Dr. 
Waagen cites the Quaternary glacial epoch, a study of whose marine fauna 
shows that the types are not destroyed but are preserved by a horizontal 
movement which thus adapts itself to the temperature relations. The 
author supposes that in the Salt Range of Australia the Carboniferous 
fauna which flourished richly in the warm currents from the east, was 
suddenly cut short at the end of the Permian by cold currents setting in 
from the north — an hypothesis that is corroborated bj' the aftinities of the 
types. This influence existed throughout the whole Triassic and Jurassic 
periods, extending far southward to the borders of the Southern sea. 
This great change in the sea fauna at the end of the Paleozoic time re- 
sulted directly or indirectly from the depressions in temperature 
which extended more or less rigorously over the whole earth with the 
exception, perhaps, of South America. The latter continent shows no 
authentic indications of glaciation either in Carboniferous or Permian 
time. l>uringthe Carboniferous glacial period that continent seems to 
have played a role similar to that of western North America in the Quar- 
ternary glacial epoch. In conclusion, the author regards it established 
beyond doubt that the glacial epoch, which extended during the Carbon- 
iferous period with very great influence over a continent which lay 
chiefly south of the equator, spread itself later in the Permian over a 
greater part of the earth's surface. Concerning the causes of this great 
temperature depression, the author can ofiter no explanation; but he 
points out as an incidental conclusion, that in the earlier as well as in the 
later perioils. the distribution of plant types on the surface of the earth, 
as revealed in their fof^sil remains, should only within certain limits be 
employed as characteristic fossils by which to determine the age of the 
strata containing them. 
Tables for tlie detennination of common minerals, VtyVrMF. "W. O. Cuosby. 
