168 Geological Society. 



Camelopardalis, Gazella, Hycena, 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 Elephants 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 meyaceros 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 notice?, 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 Eocene or 

 Miocene, and improbable in the Pliocene. 



April 28, 1880.— Robert Etheridge, Esq., E.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, C.B., F.R.S., F.G.S. 



The author referred to some 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 vertebrae were 

 said to agree most nearly with those of Dicynodon and Oudenodon. 

 The supposed sternal bone is of a rounded hexagonal form, and is 

 regarded by the author as the anterior bone of the sternum proper, 

 which is usually unossified in recent lizards, but well ossified in 

 Ornithorhynchus. In the scapula also the author pointed out re- 

 semblances to that bono in Ornithorhynchus. The humerus in its 

 general proportions, and especially in the great development of its 

 ridges, was also shown to resemble the same bone in the Mono- 

 tremes. The ungual phalanges were described as broad and obtuse, 

 probably constructed to bear claws adapted for digging, as in 

 Echidna ; the femur also resembles that of the last-named animal. 



The author remarked upon these approximations to the Mono- 

 trematous Mammalia, in allusion to which he proposed the name of 

 Platypodosaurus robustus for this animal, the humerus of which 

 was 10g inches long and nearly 6 inches broad at the distal end. 

 He also alluded to the interesting problems opened up by the study 

 of these South-African reptiles, in connexion with their possible 

 relationships to the low implacental Mammalia of New Guinea, 

 Australia, and Tasmania. 



