3i6 ALUS. (Vor.. XVIII. 



EXPLANATION OF PLATE VL 



Fig. 29. Dorsal view of the hyoid and branchial arches, showing the in- 

 sertions of the muscles. The basihyal has been pulled forward, the fifth 

 ceratobranchials pulled backward, and the bones all spread apart somewhat, 

 for better illustration. X 2. 



Fig. 30. Ventral view of the same, with the epibranchials and pharyngo- 

 branchials removed. X 2. 



Fig. 31. Lateral view of the cerato-hypohyal. ^ 2. 



Fig. 32. Lateral view of the basibranchials. X 2. 



Fig. 33. Lateral view of the basibranchials. X 2. 



Fig. 34. Ventral view of the basibranchials. X 2. 



Fig. 35. Internal, or mesial view of the mandible. X 2. 



