1869.] DR. J. E. GRAY ON THE TORTOISES. 185 
10. CatticHELys, Gray, Ann. and Mag. N. H. xii. 1863, p. 176. 
1]. DerrocuHEtys, Agassiz. 
I have not been able to examine the alveolar edge of the last three 
genera; they may belong to the next tribe. 
Section II. Hyprocutemmys. The alveolar surface of the upper 
and lower jaws broad, expanded, covering more or less of the ~ 
sides of the front of the palate, so that the internal nostrils 
open near the middle of the palate. Lower jaw strong. ‘Toes 
webbed. 
Tribe IV. Matactemmynina. The alveolar surface smooth. Toes 
strong, spreading, covered with a soft skin. Eyes subsuperior ; 
pupils annular, without any lateral spot. 
1. The upper or alveolar surface of the under jaw broad, concave, 
rather narrower on the hinder part of the side. Internal 
nostrils subposterior, behind the middle of the alveolar surface. 
* Front of the palate, before the internal nostrils, with a broad 
central groove. Eyes subsuperior (Estuarian). 
12. Matacuemmys, Gray, Cat. Shield Rept. p. 37. 
** Front of the palate, before the interior nostrils, simple. 
Eyes lateral: 
13. Damonia. 
11. The upper or alveolar surface of the under jaw wide, angular, 
concave in front, narrow and sharp-edged on the sides behind. 
Internal nostrils subanterior. 
14. GuypTemys. 
111. The upper or alveolar surface of the lower jaw narrow, sharp- 
edged in front, wider and flattened on the hinder part of the 
sides. Internal nostrils subanterior. 
15. Bexura. Skin of neck and limbs with very minute granular 
scales. 
Tribe V. Baracurina. Head large, nose rather produced ; angles 
of the mouth covered with minute scales. The alveolar surface 
of the jaws very broad, with one or two strong ridges or grooves. 
Internal nostrils subposterior. Toes elongate, weak, expanded, 
covered with small scales, united by broad webs to the claws ; 
hind feet fringed. The cavity of the thorax much contracted 
on each side at each end by broad, erect, internal, bony lateral 
plates. Asia. 
