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Show » 170 DR. A. S.'WOODWARD ON EXTINCT [Mar. 5, important reptilian fossils, however, still await description; and Dr. F. P. Moreno, Director of the La Plata Museum, has kindly entrusted them to m e for detailed study, of which the results appear in the following pages. The new specimens represent a species of the extinct armoured Chelonian Miolania; an undescribed extinct genus of Ophidians ; and a large carnivorous Dinosaur. I. AN ARMOURED CHELONIAN, MIOLANIA ARQENTINA. (Plates XV.-XVIII.) In the autumn of 1898, Mr. Santiago Roth sent me a photograph of a bony ring of a tail-sheath from the red sandstone of Chubut, which Dr. Moreno and he regarded as most closely resembling the caudal armour of the extinct Australian Chelonian, Miolania l. Early in 1899, Dr. Moreno brought the actual fossil to London for comparison with the original specimens from Queensland and Lord Howe's Island, now in the British Museum, with the result that his determination of the Patagonian fragment seemed to be confirmed. Microscopical sections, however, failed to prove identity, probably because the structure of the tissue of the new specimen was not well preserved. Dr. Moreno therefore sent another expedition under Mr. Roth to the locality whence the caudal ring was obtained; and this party was so fortunate as to find and disinter not only the skull and mandible, but also considerable portions of the carapace of a similar animal. A preliminary notice of this discovery was published in September 1899 by Dr. Moreno2, who sent the original specimens for exhibition to the Dover Meeting of the British Association3. At the same time Dr. Florentino Ameghino4 briefly recorded a similar discovery said to have been made by his brother Carlos Ameghino in the Guaranitic Formation of Sehuen and Chubut. He also placed his specimens in the family Miolaniidae, but in a new genus and species, Niolamia argentina ; although no detailed description was given to justify this arrangement. Skull and Mandible. The skull (Plates XV.-XVII.) is much depressed and triangular in shape, with the temporal fossa? completely roofed by bone, the orbits far forwards, and the single large narial opening terminal. 1 R. Owen, "Description of Fossil Remains of two Species of a Megalanian Genus (Meiolania) from Lord Howe's Island," Phil. Trans. 1886, pp. 471-480, pis. xxix., xxx. Also " On Paris of the Skeleton of Meiolania platyceps, Owen," ibid. 1888P, pp. 181-191, pis. xxxi.-xxxvii. A. Smith Woodward, "Note on the Extinct Reptilian Genera Mcgalunia, Owen, and Meiolania, Owen," Ann. Mag. Nat. Hist. [6] vol. i. (1888), pp. 85-89. 2 F. P. Moreno, " Note on the Discovery of Miolania and of Glossotherium (Neomylodon) in Patagonia," Geol. Mag. [4] vol. vi. (1899), pp. 385-388. 3 F. P. Moreno and A. Smith Woodward, "Exhibition of and Remarks on a Skull of the extinct Chelonian Miolania from Patagonia," Rep. Brit. Assoc. 1899 (1900), p. 783. * F. Ameghino, Sinopsis Geologico-Paleontologica-Suplem. (1899), p. 10. |