SYSTEMATIC REVISION 51 



aguti, but there is a slighter development of the same thing. 1 he posterior portion 

 of the pterygoid takes part in the border of the palatal vacuity, forms a part of 

 the border of the auditory notch, and aids in the closure of the posterior portion of 

 the skull. Numerous small teeth are found on the anterior process of the pterygoid 

 and on the external process. 



"The foramen magnum is bordered by four bones: (i) Exoccipital; (2 and 3) 

 the inner branches of the exoccipitals which expand broadly and unite above with 

 the (4) supraoccipital. The outer branches of the exoccipitals bend first outward 

 and then upward to the tabulare, inclosing a foramen between them and the tabu- 

 lare. Above the foramen the border line between the two inner branches of the 

 exoccipital are not so clear; it almost seems as if they inclosed between them and 

 the supraoccipital another foramen. The lower jaws are closely pressed against 

 the skull in both specimens. No observations can be made on the teeth. 



"Measurements of skull. 



"Breadth of the skull on the posterior border 10.5 



Total length in the mid (so far as preserved) 10.2 



Separation of the orbit from the posterior border ol the skull ^auditory notch) . 1.8 



Distance between orbits 3.1 



Length of orbit ca.2.7 



Breadth of orbit ca.2.6 



"Pectoral Girdle: The interclavicle is rhombic anteriorly with a long posterior 

 process. The anterior end has a rough radiate sculpture. The clavicles are wing- 

 like, the posterior end bends backwards and upwards in an obtuse angle to form 

 spatulate process so that they covered in this way the sides of the animal. The 

 proximal ends do not meet in the median line and are covered with rough sculpture. 

 There is no evidence of a cleithrum; the condition of the specimens does not permit 

 a final conclusion as to its presence. The vertebrae shown have low transverse 

 process, the neural arch is saddle-shaped and broader than long. The pre- and 

 post-zygapophyses are horizontal. The ribs are double headed (?) and the distal 

 end is expanded and shovel-shaped." 



Revised description of the genus and species: 



1. The skull a little broader than long; blunt anteriorly. 



2. Orbits large, more in the posterior half of the skull than in the middle, 



looking laterally. 



3. Not determinable. 



4. Not determinable. 



5. Not determinable. 



6. Basioccipital and basisphenoid not large. 



7. Supraoccipital plates, nearly vertical but occupying a considerable space, 



are on the upper surface of the skull. 



8. Skull with definite reticulate sculpture. 



9. Not determinable. 



10. Cleithrum absent. 



11. Not determinable. 



This genus was reported by Broili to have both prosquamosal, squamosal, and 

 quadratojugal bones, but a reexamination of the specimen by Dr. Broili and the 

 author shows that there are but two bones on the side of the skull, as in the Pario- 

 tichidce and Captorhinidce. The presence of an intertemporal bone justifies its 

 separation as a distinct family. (See also Williston, Journal of Geology, vol. xix, 

 p. 232.) 



