AMERICAN LABYRINTHODONTIDM 599 



The dimensions of the skull and of the openings in the roof and 

 floor are as follows: 



mm 



Length along margin of jaw 580 



Length along median line from tip of snout to posterior 



end of quadrates 540 



Length from supraoccipital to tip of snout .... 445 



Greatest breadth 350 



Breadth at posterior end of orbits 325 



Breadth at posterior end of nares 233 



Distance from back part of nares to fore part of orbit . 185 



Distance of orbit from supratemporal 120 



Distance apart of nares 100 



Distance apart of orbits 90 



Length of nares 31 



Breadth of nares 29 



Length of orbits 53 



Breadth of orbits 56 



Length of palatine foramen . . 180 



Breadth of palatine foramen go 



Distance from tip of skull 200 



Distance from end of condyle 65 



Distance from internal nares 65 



Length of internal nares 45 



Breadth of internal nares 27 



Distance from tip of snout no 



Length of infratemporal foramen 175 



Breadth of infratemporal foramen 80 



Under side of skull. — The under side of the skull is not in one 

 plane, but is arched upward very strongly along the median line 

 posteriorly. This arching is caused by the inner wings of the ptery- 

 goids turning abruptly upward. 



The parasphenoid is comparatively much shorter than in Broili's 

 specimens. One of the skulls which he describes is about ^S cm long, 

 and has a parasphenoid 26 cm in length, while the skull described 

 in this paper is 45 cm long and has a parasphenoid only 22 cm in length. 

 The parasphenoid is expanded in the middle and in front of the expan- 

 sion tapers gradually to a point between the prevomers. Behind the 

 expanded part it tapers gradually to near the posterior end, where 

 it broadens slightly, separating the pterygoids and articulating with 

 the exoccipitals. The parasphenoid does not separate the pterygoids 



