282 Reports and Proceedings— 
of the genus Rhopalodon; but as there are some marked dif- 
ferences, the author proposes to name it Cliorhizodon orenburgensis. 
2. “The Classification of the Tertiary Period by Means of the 
Mammalia.” By Prof. W. Boyd Dawkins, M.A., F.R.S., F.G.S., 
Professor of Geology in Owens College. 
The author, after some introductory remarks on the value of 
Vertebrata and Invertebrata in classification, pointed out that the 
Mammalia become of especial value in the Tertiary period as under- 
going more rapid change than the other classes, from their being, as 
it is happily termed, en pleine évolution. He discussed the cha- 
racteristics of each of the great periods, as defined and limited by 
their Mammalia, pointing out that throughout the Hocene these 
frequently exhibit relations more or less marsupial. Indeed, it is 
not till the close of the Lower Miocene that the traces of this 
relationship are lost. In the Middle Miocene, Sus, Cervus, Antilope, 
Felis, Lutra, and Castor appear for the first time, and the higher 
Apes were present in Huropean forests. In the Upper Miocene 
Camelopardalis, Gazelle, Hyena, and Hystrix appear. During the 
Pliocene several important genera disappear from the world or from 
Europe—among the latter the Apes, at the close of the Upper 
Pliocene. Oxen, Horses, Bears, and Hlephants appear. Great 
changes took place in the Pleistocene ; seven species survived into it 
which are now extinct, and of new comers there were fourteen living 
and seven extinct species. Cervus megaceros is the sole survivor 
from the Pleistocene to the prehistoric period which has since 
become extinct. The paper concluded with some remarks on the 
latter part of the first and the second period, which, however, as 
forming the subject of previous notices, was treated more briefly. 
The author remarked that a study of the development of the Mam- 
malia renders it hopeless to expect to find Man in the Hocene or 
Miocene, and improbable in the Pliocene. 
TI.—April 28, 1880.—Robert Etheridge, Esq., F.R.S., President, 
in the Chair. 
The following communications were read :— 
1. “Description of Parts of the Skeleton of an Anomodont 
Reptile (Platypodosaurus robustus, Ow.) from the Trias of Graaff 
Reinet, South Africa.” By Prof. Owen, O.B., F.R.S., F.G.S. 
The author referred to certain Triassic reptiles from South Africa, 
already described by him, as showing certain resemblances to 
implacental Mammals. Another still more interesting indication of 
such resemblances is furnished by some remains from Graaff 
Reinet received from Mr. E. J. Dunn. These consist of some thoracic 
vertebrae with portions of ribs, a sternal bone, a scapula, and a right 
humerus, found imbedded in one mass of rock, and of a femur and 
phalanges, and a pelvis in another mass. : 
The author described these bones in detail. The vertebras were 
said to agree most nearly with those of Dicynodon and Oudenodon. 
The supposed sternal bone is of a rounded hexagonal form, and is 
