10 Watson, Notes on some British Mesozoic Crocodiles. 



differences of generic value are to be seen, and the only 

 character recorded by Owen and Lyddeker which would 

 serve to separate it from that genus is concerned with the 

 position of the posterior nares. In Macrorliynchtis these 

 are placed very far back — nearly as in a modern gharhial ; 

 whereas in Petrosuchus they are said to be in the middle 

 of the skull and to be flanked by a pair of projections. 

 Actual examination of the specimen shews that it is far 

 too badly preserved to justify any such contention ; the 



Q_^ 



Fig. 3. Dorsal surface of the type skull of PhoUdosmirtis 

 decipieiis (ohm Petrosuclms laevidens). x ^ to show the 

 sutures between the various bones which are only partly 

 floured by Owen. 



lower surface is crushed, and it is impossible to dis- 

 tinguish between the matrix and the bone, to which it 

 very tightly adheres. The two projections, which have 

 been supposed to mark the position of the anterior edge 

 of the posterior nares, are really formed by the crushing 

 through of the descending processes of the pre-frontais, 

 which articulate with the anterior ends of the pterygoids. 



