SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 76 



PLATE 1 



Comparison between the skull of a toothed cetacean, fig. i, and that of a 

 baleen whale, fig. 2, to show the differences in method of telescoping described 

 on page 4; dorsal and ventral aspects. (For comparison of lateral aspects 

 see plate 6.) 



Fig. I. Steno. No. 49983, U. S. Nat. Mus. (The tympanic and periotic bones 

 have been lost. The absence of the orbital plate of the maxillary is 

 shown in fig. ib by the exposed line of contact between the maxil- 

 lary and the anterior border of the frontal.) 



Fig. 2. Balicnoptera. No. 236680, U. S. Nat. Mus. (The right tympanic bone 

 and the left jugal have been lost. The great development of the 

 orbital plate of the maxillary is shown in fig. 2b by the dotted line 

 indicating the position of the anterior border of the frontal hidden 

 in this view by the orbital plate.) 



