294 



THE WHALEBONE WHALES OF THE WESTERN NORTH ATLANTIC. 



In. and tooths. 



Breadth of beak at f its length from base (curved) 6.00 



Breadth of maxillary at J its length from base (curved) 1.50 



Breadth of premaxillary at f its length from base (curved) 1.25 



Length of lower jaw in a straight line 47 oo 



Height at coronoid process 



Length from posterior end of condyle to coronoid process. 



Height of ramus at middle 



Amount of curve 



Length of otic bullse 



6.00 



7-5 

 4.00 

 6.50 

 3-5 



The osteological material of this species in the National Museum available for 

 the study consists of (1) a skull from Puget Sound (Cat. No. 12177, U. S. N. M.), 

 presented by Capt. C. M. Scammon about 1872, and very probably belonging to 

 the individual from which the original description was drawn, and hence the type 

 of the species ; (2) a skull from St. Paul Id., Pribilof Group, Alaska (Cat. No. 61715, 

 U. S. N. M.), collected by Mr. C. H. Townsend of the U. S. Fish Commission. 



Measurements of these skulls, reduced to percentages of the total length, are 

 given on page 197, with those of specimens of B. acuto-rostrata. It will be observed 

 by reference to the measurements that the Pacific specimens agree in all but one or 

 two of the proportions given with those from the Atlantic in the closest possible 

 manner. In each proportion in which one of the Pacific skulls differs from the 

 Atlantic ones, the other harmonizes with the latter, so that there cannot be said to 

 be a constant difference in any of the proportions between the specimens from the 

 two oceans. For convenience, the actual measurements of the two Pacific skulls, 

 and of the Norway skull, No. 13877, are given below : 



BALMNOPTERA ACUTO-KOSTRATA LAC. AND B. DAVIDSONI SCAMMON. SKULL. 



1 All straight, unless otherwise stated. 



2 Add 2 in. for breakage. 



