726 DR. .T. E. GRAY ON THE SKULLS AND [Nov. 4, 



4. Testudinella. 



Toes 4 . 4. 



We have only one specimen of this animal, the skull of which 

 is in the skin, and therefore the alveolar surface cannot be examined; 

 but it is like Peltastes graca in external appearance, being only 

 known from it by wanting one front toe. 



Testudinella horsfieldi, Gray, Cat., Append, p. 13. 



5. Chersina. 

 Toes 5.4. Intergular plates united together and produced for- 

 wards. Alveolar process of the upper jaw simple, with a slight 

 groove on the hinder part of the lateral margin. The internal 

 nostrils in the front of a deep concavity that is very slightly con- 

 tracted on the sides behind. Lower jaw sharp-edged and concave 

 on the inner surface in front, and with a prominent inner edge on 

 the hinder part of the side fitting into a groove in the upper jaw. 

 Front of beak rounded, with a groove on the lower side of each 

 nostril towards the margin, which is marked with three close teeth. 



Chersina angulata, Gray, Cat., App. p. 14. (Plate LX. fig. 6, 

 alveolar processes of jaws). 



Section III. Alveolar surface of vpper jaw narrow in front, broad 

 behind, triangular on the sides, with a sharp edge on each side 

 of the loioer jaw, linear, narrow, with a rather sharp edge on 

 each side. 



Tribe V. Homopina. 



1. Homopus. 



Toes 4.4. Alveolar surface of the upper jaw triangular on each 

 side, with a sharp edge on the outer side and on the inner side of the 

 hinder part. Loner jaw thin, weak, slender ; alveolar surface linear, 

 rather broader in front, with a sharp slightly raised edge on each 

 side. The internal palate broad in front to the front of the alveolar 

 edge, rather wider in the middle, and slightly contracted behind. 



Homopus areolatus, Gray, Cat., App. p. 15. (Plate LX. fig. 5, 

 alveolar processes of jaws.) 



Tribe VI. Pyxidina. 



Alveolar surface of the upper and lower jaw linear, with a sharp 

 outer edge. Lower jaw slender and weak. The front lobe of the 

 sternum separated by a transverse suture and covered with the 

 gular and postgular plate. 



1. Pyxis. 



Skull short. Forehead flat. Orbits large. Nose-hole square, 

 with a deep wide notch in the upper margin towards the frontal 

 bone ; the lower edge transverse, with a central prominence. Inter- 

 maxillary rather high. Tympanic cavity narrow, erect, and the 

 hinder part of the tympanic bullae rather produced. 



