312 ALUS. [Vol. XVIII. 



EXPLANATION OF PLATE IV. 



Fig. 5. Dorsal view of the skull. X 2. 



Fig. 6. Dorsal view of the skull, with the purely dermal bones re- 

 moved. X 2. 



Fig. 7. Lateral view of the skull. X 2. 



Fig. 8. Median view of a bisected skull. X 1J/2. 



Fig. 9. Ventral view of the skull. X 2. 



Fig. id. Posterior view of the skull. X 2. 



