1869.] DR. J. E. GRAY ON THE TORTOISES. 179 
superior, often rather close together. Thorax covered with horny 
plates. Sternum attached to the thorax by a bony symphysis, 
generally small (compared with the size of the thorax) and cross-like, 
sometimes large (nearly as big as the thorax); sternal shields vari- 
able in number from 7 to 11, never 12. Toes short, spreading, 
webbed to the claws, shielded above. 
Skull with a well-developed zygomatic arch, extending from the 
orbit to the tympanic cavity, leaving a large wide space for the tem- 
poral muscles. Palate flat; internal nostrils anterior. Alveolar 
plate narrow, simple. Iris annular, without any spot on the sides. 
Section I. CrucisterwNA. The sternum small, cross-like, narrow 
at the ends. Head and tail large. 
Tribe I. CuorLtyprarna. Sternum solid, cross-like, acute before ; 
sternal plates 10, with a broad one (the displaced abdominal 
plate) on each side over the produced sides of the sternum. 
Palate flat; internal nostrils anterior. Alveolar plate flat, 
rather broad. 
1. MacrocuE ys, Gray, P. Z.S. 1855, p. 200= Gypsochelys, Agas- 
siz; (skull figured) Gray, Catalogue of Shield Reptiles, t. 38, 
39, 40. The alveolar plate very broad. Eyes lateral, distant. 
2. Cuxetypra, (skull figured) Gray, Cat. Shield Reptiles, t. 38 & 
40. f. 2. Alveolar plate moderate. Eyes superior, rather close 
together. 
Staurotypus salvini’. 
