54 A REVISION OF THE COTYLOSAURIA OF NORTH AMERICA 



probably also bearing teeth, and apparently small transpalatines. The pterygoids 

 are fairly large and have rows of small teeth. 



"The occipital condyle is flat. 



"The vertebrae are large and massive and have intercentra. The zygapophyses 

 are veiy broad. The ribs for the most part are single-headed. 



"The shoulder girdle has a large scapula with a well-developed acromion, 

 large precoracoid and fairly large coracoid. There is well-developed cleithrum, 

 fairly large clavicles, and a massive T-shaped interclavicle. 



"The humerus is very massive and has a large deltopectoral ridge. The ulna 

 has an olecranon process. 



"The carpus, so far as known, appears to be similar to that of most early reptiles. 



"The digital formula is unknown. It has been stated to be 2, 3, 3, 4, 3, but 

 in the closely allied Propappus it is most probably 2, 3, 4, 5, 3, two digits having 

 certairily more than 3 phalanges. 



"There are apparently no abdominal ribs. 



"The pelvis is remarkable for having the ilium large and directed forward as 

 in Mammals and the higher Therapsida. 



"The teeth are pecularily specialized. Externally they are markedly convex, 

 the inner side being nearly flat. Round the edges are 7 or 9 large cusps arranged 

 in a semicircle." 



Genus ANTHODON Owen. 



Owen, Cat. Foss. Rep. South Africa, 1876, p. 14. 



Imperfectly known. Skull more vaulted than in Pareiasaurus. Teeth with 

 short, compressed, and anteroposteriorly expanded crowns, having a convex, sub- 

 trenchant free edge, marked by numerous crenulations, roots long and narrower 

 than the crowns. Centra of the dorsal vertebrae with deeply cupped terminal 

 faces, and no evidence of the presence of intercentra. 



Genus PROPAPPUS Seeley. 



Seeley, Proc. Roy. Soc, vol. XLiv, No. 267, 1890. 



Broom, Annals of the South African Museum, vol. iv, pt. vui, 1890, p. 351. 



Type: A humerus. No. 36250 in the British Museum. 



Homotype: The "greater part of a large skeleton," now in the South African 

 Museum. Described by Broom. 



Description of the homotype: Skull represented by fragments of a maxilla and 

 the mandibles. Mandibles with two projections from the lower edge, instead of 

 one as in Pareiasaurus. The crowns of the teeth flattened, semicircular, with 

 eleven cusps on the maxillary teeth; cusps on the mandibular teeth similar to those 

 on the maxillary but smaller. Vertebrae as in Pareiasaurus, the centrum rather 

 slender and elongate; biconcave but not deeply excavated. Intercentra present. 

 Transverse process broad and powerful, spine low and short. Limb bones and 

 girdles differing little from Pareiasaurus. Tarsus with a single proximal element; 

 distal tarsals probably small and largely cartilaginous. Foot broad and short, 

 digital formula almost certainly 2, 3, 4, 5, 4, certainly more than 2, 3, 3, 4, 3. 

 "Whole back and probably sides covered with a carapace of bony plates somewhat 

 after the manner of a crocodile." There is no evidence of any plastron. 



Genus ELGINIA Newton. 

 Tran». Roy. Phil. Soc., vol. 184, pp. 43'-503. 



Type: The cast of a skull from the Elgin Sandstone. Preserved in the Museum 

 of Practical Geology, London. 



