SKULLS OF CYXOUOXT REPTILES. 899 



Gcdesaurus clifFered greatly from tlie type, and gave it the name of 

 Thrinaxodon liorhinus. 



There is, in my opinion, not the least doubt that Seeley was 

 right in regarding the 1887 skull as belonging to a very different 

 animal from the 1859 one. In fact it seems strange that any one 

 should ever have thought them the same. Galesaurus has a 

 dental formula apparently of i. ;J, c. ':, m. || ; the 1887 specimen 

 has a formula of i. y, c. \, m. \. In the 1859 specimen 10 molars 

 occupy 20 mm.; in the 1887 specimen 7 molars occupy 20 mm. 

 But while the two supposed Galesaurus specimens represent 

 difterent genera, two other imperfect specimens in the British 

 Museum show that the 1887 specimen is the same animal as was 

 described in 1876 as Nythasaurus larvatus. Hence the well- 

 known skull which is figured in various text-books as Galesaurus 

 must in future be called Nythosaurus. 



Nythosaurus is a much higher type than Bauria : but though 

 it comes faiily close to the higher Cynodonts such as Cynognathus, 

 it should, I think, be taken as the representative of a distinct 

 family, the Galesauridce. From the various specimens in the 

 British Museum it is possible to make an almost complete restora- 

 tion of the skull. 



Text-fig. 170. 



Side view of the skull of Nj/tlwsaurus larvaius. I'he drawing is inainly tliat of tlie 

 best preserved specimen in the British Museum, Compared with tlie other 

 specimens and slightly restored from them-. The teeth are represented in the 

 mature condition. 



The septomaxillary though smaller than in Bauria still appears 

 on the face. The nasal is large and very broad at its upper end. 

 The lachrymal is large, and though the pi-efrontal is only of 

 moderate size, it joins with the postorbital and completely shuts 

 out the frontal from the orbit. The postorbital forms with the 



