460 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



[VOL. SO 



EXPLANATION OF PLATES 



Plate LIX 



Fig. 1. Type specimen of Scliizodelphis crassangulum (Case), (=Prisco- 

 delpJiinus ? crassangulum Case). Superior surface of the ros- 

 trum. One-third natural size. 



Fig. 2. The same. Superior surface of the mandible. One-third natural 

 size. 



Fig. 3. The same. Inferior surface of the rostrum. One-third natural 

 size. 



Fig. 4. The same. Inferior surface of the mandible. One-third natural 

 size. 



Plate LX 



Fig. 1. Type specimen of Schisodelphis crassangulum. Left side of ros- 

 trum and mandible. One-third natural size. 



Fig. 2. The same. Left zygomatic process of the temporal, exoccipital, and 

 occipital condyle. Posterior view. One-half natural size. 



Fig. 3. The same specimen and parts. Anterior view. One-half natural 

 size. 



4. The same specimen. Left tympanic bulla. Inferior surface. One- 

 half natural size. 



5. The same. Internal surface. One-half natural size. 



6-1 1. Fragments of tympanic bullae of S. crassangulum from Chesa- 

 peake Beach, Md. (In the U. S. National Museum.) One- 

 half natural size. 



Fig. 12. Fragment of the symphysis of the mandible of S. crassingulum 

 from Chesapeake Beach, Md. (In the U. S. National Museum.') 

 Upper surface. One-half natural size. 



Fig. 13. The same fragment. Lower surface. One-half natural size. 



Fig. 



Fig. 

 Figs 



BS = Basisphenoid. 

 ME — Mesethmoid. 

 MX = Maxilla. 

 PMX = Premaxilla. 



PT — Pterygoid. 

 V = Vomer. 

 XO = Exoccipital. 

 ZG = Zygomatic. 



