68 MIOCENE FAUNA. 



rather strongly convex carapace. At the present day they in- 

 habit North America and India, and no species occurs in Europe, 

 whilst in Miocene times eight species inhabited the Swiss rivers 

 and lakes. Of two large species (Emys Laharpii, Pict., and E. 

 Charpentieri, Pict.) numerous fragments have been obtained from 

 the lignite-pits of the Paudeze; a third species (E. Gaudini, 

 Pict.), distinguished by the narrow and nearly parallel- sided 

 plates of the carapace, has been furnished by the sandstone of 

 the Solitude (near Lausanne) ; a fourth (E. Nicoleti, Pict.) by 

 the freshwater limestone of La Chaux-de-Fonds ; and a fifth 

 (E. Wyttenbachi, Bourd.) by the freshwater limestone of the 

 Rappenfluh near Aarberg. To these must be added two species 

 discovered in the Aargau, and three near Rochette, besides a 

 small species from (Eningen (E. scutella, Meyer). None of 

 these river-tortoises have yet been found so perfectly preserved 

 as to enable Professor Heer to ascertain the analogous living 

 species. 



In all the above-mentioned tortoises are found a hard solid 

 carapace, with the plates closely fitted together ; but in the soft 

 tortoises (Trionyx) the flattened body is covered with a smooth 

 leathery skin. The head, which is borne upon a long neck, is 

 produced into a short beak the tail is very short, and the feet 

 have only three toes. These animals, which differ very much 

 in appearance from the other tortoises, inhabit the Nile and the 

 rivers of Mesopotamia and India ; one species, also, is found in 

 the southern United States. Formerly three species lived in 

 the Swiss region; one (Trionyx Teyleri, Winkl.) was discovered 

 at (Eningen, a second at Yverdon, and a third large species, 

 measuring G'30-0'35 metre (or 1 1*8-13* 7 inches) in diameter, 

 on the Paudeze. Their remains, however, are imperfect, suffi- 

 cient only to characterize the genus, but furnishing no satisfac- 

 tory information as to their analogies with living species. 



Trachyaspis is a peculiar extinct genus, one species of which 

 (T. Lardyi, Meyer) has been discovered in the Miocene of the 

 Tour de la Moliere. It is, however, too imperfectly preserved 

 to allow its relationships to be ascertained. In the markings on 

 the rib-plates it resembles the soft tortoises ; but it was clothed 

 with scales. 



