I.—On a New Specimen of the Mesosaurian Reptile, Stereosternum tumidum, from San Paulo, Brazil

Abstract

When in Rio de Janeiro last October, Dr. Orville A. Derby gave me for publication in the GEOLOGICAL MAGAZINE the photograph of a fine new specimen of Stereosternum tumidum, reproduced in the accompanying Plate V. Like the type-specimens discovered by Dr. Derby, it was obtained from a light-grey limestone in a quarry on the estate of Senhor Antonio Machado de Campos, near the town of Limeira, in the State of San Paulo, Brazil. It is interesting as showing for the first time the general proportions of the trunk and tail of this strange extinct reptile; and it also permits the identification of another fossil from the same formation, now in the British Museum, which has hitherto escaped notice.