CYNODONTIA. 267 



the length of the head, and the anti-brachium about two-thirds 

 the length of the humerus. The fortunate preservation of the 

 skull has brought to light modifications of the lacertine struc- 

 ture leading towards Chelonia and birds which before were 

 unknown. 



The cranium of a Ehynchosaurian reptile with obscure 

 maxillary dentations,* has been discovered in the sandstones, 

 containing the Leptopleuron, near Elgin ; and adds to the 

 probability of their triassic age. 



Fam. — Cynodontia. 



A pair of teeth in each jaw resembling in shape, position, and 

 relative size to the other teeth, the canines of carnivorous 

 mammals, and dividing the incisors from the molars. 



Genus Galesaurus, Ow. — This genus is founded upon the 

 fossil skull of a reptile (fig. 96, i and z), from the sandstone of 

 Ehenosterberg, S. Africa, exhibiting that remarkable resem- 

 blance to the mammalian carnivorous dentition, which has led 

 to a foundation of a family for its reception in the group of 

 reptiles characterized by the anomalous departures from the 

 type of dentition in the great Saurian order of Cuvier. 



The skull of the Galesaurus planiceps is, as the specific 

 name implies, depressed and flat ; tapering from the broad 

 zygomatic region to the muzzle. The occipital plane is inclined 

 from below upward and forward, is continuously ossified, is 

 pitted by the insertion of powerful muscles, and is bounded 

 laterally by ridges, converging upward and dividing the 

 occipital from the temporal fossa?. The parietal crest bifur- 

 cates to surround an elliptical "foramen parietale ;" and the 

 divisions thence gradually diverge to the post-frontals. The 



* Prof. Huxley has referred this fossil to a genus Hyperodaphodon, because 

 it appears to possess palatal teeth : but these may have been present in 

 Rhynchosaurus. 



