1894.] Organisation, and Classification of Fossil Reptilia. 28 



powerful tooth : its extremity is worn obliquely. There appear to 

 be six premolar teeth, all contained in a length of half an inch. The 

 maxillary teeth are packed in close succession, as in Rodents. There 

 are nine molar teeth. In the middle, where they are largest, four 

 occupy the length of 1 in. The contour of the crowns of these 

 molars is convex from front to back, as in many mammals ; and in 

 this genus they are all behind the hard palate. The external cusp is 

 prominent, and a ridge descends inward and backward from it upon 

 the large flattened ledge of the crown, which is worn almost level, as 

 though there were a rodent-like horizontal movemeut of the lower 

 jaw. 



A lumbar vertebra, found in developing the back of a skull, may 

 possibly belong to this genus. 



With the skulls a right humerus was found, which is of ins. long. 

 It shows the reptilian transverse elongation of the proximal articula- 

 tion, combined with characters which are paralleled in the marsupial 

 mammals and Garni vora. 



The genus Microgomphodon is known in the first place from a skull 

 2^ ins. long, shaped much as in Galesaurus, but distinguished by the 

 comparatively large size of the front pair of mandibular incisors, 

 and the strong, conical, pointed character of the incisor teeth. The 

 canine teeth are not differentiated from the incisors. The molars 

 show in lateral aspect small blunt cones ; but on their palatal aspect 

 have flattened crowns with many small cusps. All the teeth have 

 short roots. There are three incisors on each side in both the man- 

 dible and skull, one canine, and five molars. 



There is ground for associating with this genus an imperfect 

 skeleton, which, in addition to indicating ten early dorsal ribs, and 

 fourteen lower dorsal vertebrae and ribs in advance of the acet- 

 abulum of the femur, shows the left bumerus, portions of right and 

 left scapulae, portions of the coracoid, clavicle, interclavicle, the 

 pelvic bones, all the bones of the hind limb, distal ends of ulna and 

 radius, carpus, metacarpus, a,nd five digits. With these a fragment 

 of a skull is associated, which has the maxillary and mandibular 

 teeth in contact, showing the animal to be Gomphodont ; while so 

 much as is preserved closely resembles the skull of Microgompttodon, 

 and apparently the canine was not larger than the premolar. This 

 skeleton demonstrates a close general resemblance of plan between 

 the Gomphodontia and Cynodontia. The lower dorsal ribs have a 

 transverse lozenge-shaped enlargement, which, however, is less de- 

 veloped than in Cynognathus. The pelvis is exposed on the ventral 

 side. As in most, if not all, South African Therosuchia, it shows no 

 indication of median division between the pubic bones, while the 

 ischia retain their individuality. 



The pubis articulated to a short tubercle on the ilium. The blade of 



VOL. LVI. U 



