U.S. NATIONAL MUSEUM 



BULLETIN 294, PLATE 16 



Right Periotic and Right Tympanic Bulla, USNM 23636, Halicetus ignotus 



1, tympanic or ventral view of right periotic; 2, cerebral or internal view of right periotic; 3, ventral view of left tympanic 

 bulla; 4, dorsal view of left tympanic bulla; 5, external view of left tympanic bulla. 



