898 BU. R. BROOM OX THE 



The large foramen for nerves ix., x., xi., and xii. lies by tlie side 

 of the basioccipital and in front of a bone which is probably part of 

 the opisthotic. ISTerve xii. enters the foramen exactly as it does 

 in the higher Cynodonts. On the inside of the skull it has two 

 small distinct canals, which pass forwards and both unite with 

 the large foramen. 



The bone which is supposed to be the stapes is shown in fig. 8 

 (PI. XLYI). It is apparently a little displaced forwards. 



The lower jaw has a faii*ly large surangular and angular, the 

 dentary being considerably in front of the articular region. 



Taking all the characters into consideration, Bauria becomes 

 one of the most interesting intermediate types ever discovered. 

 Though an undoubted Cynodont, it I'etains many of the Thero- 

 cephalian characters. On the other hand, though on the whole 

 it is less mammal-like than the highter Oj'nodonts, it has some 

 mammalian characters which the others have lost. 



The following are TheroCephalian characters usually lost in 

 Cynodonts blit retained in Bauria : — 



1. Large septomaxillaries forming part of the facial surface. 



2. Moderate prefl-ontab. 



3-. Large frontals forming most of the interorbital region. 



4. !Peeble z3^gomatic ai'ch. 



5. The two occipital condyles so imperfectly separated as to 



represent practically a single condyle-. 

 B-. Large size of angular and slirangular. 



7. Shape of the articular. 



8. Simple condition of the mOlar teeth. 



In the following chAracters Bauria is nearer to the ms^mmalian 

 ancestor than are the higher Cyilodonts ': — 



1-. Lal'ge size of septomaJiillaries and development on face. 

 A somewhat similar condition is found in pl-imitive 

 Multitlibei'culata (e. g. Tritylodon), also in Monotremata, 

 as shown by Gaupp in Echidna embryo-. 



2-. Large frolitals. 



3. Complete loss of parietal foramen-. 



4. Absence of postorbital arch. 



5. Simple condition of molar teeth-. 



Ky'thosaurKS: 

 (Text-fig. 170.) 



"ithe type of Galesaii,ri(,s planiceps is a somewhat cru'shed Skull 

 with the bones in an unsatisfactory condition for showing sutures. 

 No second specimen of Gahsaurus has ever been discovered. 

 In 1876 Owen described an imperfect skull as Nythosaurus lav- 

 vatus. In 1887 he described another skull in fairly good preserva- 

 tion which he believed to be another specimen of Galesau7^us. 

 Seeley in 1894 showed that this supposed second specimen of 



