312 OW THE FOSSIL TEBTEBUATA OP SOUTH AMEMCA. [Mar. 16, 



able to make brief visits to Rio de Janeiro in Brazil and to 

 Montevideo in Uruguay. 



In Brazil at present three features of interest claimed attention. 

 The Cretaceous Formations in the provinces of Ceara and Babia bad 

 yielded a large number of remains of marine fishes closely similar to 

 those from deposits of the same age in other parts of the world ; 

 and from the neighbourhood of Babia, within the last few years, 

 Mr. Joseph Mawsou had obtained numerous reptilian bones, 

 referable to Mesozoic crocodiles, pterodactyles, plesiosaurs, and 

 probably dinosaurs. Certain bgnites occupying isolated basins 

 among the old rocks in the province of Sao Paulo were crowded 

 with the skeletons of Teleostean fishes evidently of a comparatively 

 modern Tertiary period. These were being collected by Dr. 

 von Jheriug for the Sao Paulo Museum, and by Mr. John Gordon 

 for the British Museum ; and when examined in detail, it seemed 

 likely they would afford much information concerning the immediate 

 ancestors of the existing Brazilian freshwater fish-fauna. A thii'd 

 geological formation of special importance was a series of limestones 

 extensively developed in the province of Sao Paulo, whence 

 Dr. Orville A. Derby some j'ears ago had obtained the remarkable 

 primitive aquatic reptile, Siereostemum tnmidum. As originally 

 recognized by Prof. E. D. Cope, who had described this animal, it 

 was extraordinarily similar to Mesosaurus of the Karoo Formation 

 of South Africa — a series of early Mesozoic deposits specially 

 characterized by extinct reptiles which had often been regarded 

 as the possible immediate ancestors of the Mammalia. Dr. Derby 

 had recently found a new specimen of Stereostermnn exhibiting 

 almost its complete skeleton, including the remarkably long tail ; 

 he had also lately met with an undoubted Labyrinth odont tooth, 

 and there was every indication that before long the important 

 Karoo fauna would be discovered in the South American area. 



The Uruguayan National Museum in Montevideo contained 

 nothing of much palfeontological intei'esfc ; and the collection of 

 bones of extinct Mammalia from Uruguay, made by Dr. Conrad 

 Moeller, had been presented by that gentleman a few years ago to 

 the University of Christiania, jN'orway. 



The National Museum of Argentina at Buenos Aires, under the 

 direction of our Corresponding Member, Dr. Carlos Berg, contained 

 the fine collection of Pleistocene Mammalia described by the late 

 Dr. Burmeister, all well preserved and beautifully mounted. 

 There was also a large collection of late Tertiary fish-remains from 

 the neighbourhood of the city of Parana. The study of these would 

 supplement in an interesting manner the results obtained from 

 the lignite fishes of Sao Paulo. 



Modern progress, however, in the discovery of the extinct 

 vertebrate fauna of the Argentine EepubHc was best illustrated not 

 in the National Museum, but in the Buenos Aires State Museum, 

 founded by our Corresponding Member, Dr. F. P. Moreno, at La 

 Plata in 1885. The more important specimens had already been 

 briefly described and well figured in the publications of the Museum ; 



