IO64 CLASS REPTILIA. 



{Ptychognathus) there is also a pair of tusk-like upper teeth, but 

 the skull is angulated, with strong ridges on the maxilla, the nares 

 far behind the muzzle, and only a very narrow supraoccipital bar 

 above the foramen magnum. The typical species are from South 

 Africa, but another representative of the genus occurs in the 

 Gondwanas of Central India, which was originally described as 

 Dicynodon orientalis. A very imperfect and flattened skeleton from 

 the Karoo system has been made the type of the genus Cirogna- 

 thus, which is said to be characterised by the small size of the 

 canine-like tooth, and the presence of only two phalangeals in all 

 the digits except the third. It appears, however, that these alleged 

 differences do not really exist, the difference in the humerus being 

 due to a comparison of opposite aspects, and the number of 

 phalangeals being apparently normal, so that this form probably 

 belongs to Dicynodon. The same remark will apply to part of a 

 skeleton from the same beds upon which the genus Eurycarpus has 

 been founded. The genus Udenodon (Oudenodon) is characterised 

 by the total absence of teeth (fig. 985, b), but is otherwise so 

 closely allied to Dicynodon that it must certainly be included in the 

 same family. The nares are somewhat approximated to the orbits, 

 and the profile of the muzzle is rounded. It occurs in the Karoo 

 system of the Cape Colony ; and some of its representatives at- 

 tained very large dimensions. Cistecephalus (Kistecephalus) com- 

 prises smaller forms from the same beds, in which the skull is much 

 depressed, with the orbits directed frontally. There was a pair of 

 tusks in the maxillae. 



The name Platypodosaurus has been applied to a considerable 

 portion of the skeleton of a Dicynodont, from the Karoo system, of 

 which the skull is unfortunately unknown, and which may prove to 

 be identical with Udenodon, unless it belong to Endothiodon. The 

 remarkably Mammalian structure of the pelvis, in which there is 

 a small obturator foramen between the pubis and the ischium, is 

 fully noticed in Sir R. Owen's description of the specimens. 



Family Endothiodontid^e. — The remarkable genus Endothi- 

 odon, comprising large reptiles from the Karoo system of the Cape, 

 forms the type of a family distinguished from the preceding by the 

 presence of teeth on the palate. The skull presents a strong gen- 

 eral resemblance to that of Udenodon, but the muzzle is more 

 elongated, and the nares are terminal and overhung by the massive 

 nasals. The alveolar borders of the jaws are trenchant, but the oral 

 surface of the palate and mandible carry one or more longitudinal 

 rows of columnar and cylindrical teeth. The remarkably Mam- 

 malian type of the palate of Endothiodon is noteworthy. The skull 

 from the same deposits described as Theriognathus seems to belong 

 to Endothiodon. 



