294 THE WHALEBONE WHALES OF THE WESTEKN NOETH ATLANTIC. 



In. and looths. 



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



Breadth of maxillary at | 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 00 



Height at coronoid process 6.00 



Length from posterior end of condyle to coronoid process 7.50 



Height of ramus at middle 4.00 



Amount of curve 6.50 



Length of otic bullae 3.50 



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

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

 presented by Ca[)t. C. M. Scammon about 1872, and ver}' 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 propoition 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 : 



BAL^NOPTERA ACUTO-ROSTRATA LA.C. AND B. DAVIDSONI SCAMMON. SKULL. 



Mea.'iurement. 



Length of skull (condylo-premaxillary) 



" beak 



" maxilla 



premaxilla 



Ant. border foramen margin over vertex to tip of beak 



Ditto to upper border of occiput 



Greatest breadth of skull 



Breadth at base of beak 



" " middle of beak 



orbital border of frontals 



Greatest breadth of maxilla behind base of beak 



between outer borders of both premaxills 



" " ** i««»» ** ** *' ** 



mner 



From vomer at ant. end of palate through to vertex 



Inner margin nasal processes of max. to end of orbital process of max . . 



Outer edge of premaxilla to end of orbital process of maxilla 



) o 



in. 

 60.5 



3^-75 



45-5 

 63.0 



17.0 



34-5 

 20.5 



12-5 



31-5 

 3°-S 

 8.25 



5-5 



13-75 



17-75 

 16.0 



^1- 



►?• -2 -a 



6, .5 



38.0 



45-25 



64.0 



17.0 



35-25 



21-5 



12-75 

 32-75 



9-5 



6-5 

 15-S 

 19-25 

 16.0 



S 



z's' 



59-25' 

 36.0^ 



44-5" 

 60.5' 

 16.0 



33-5 

 20.0 



II. o 



3°-5 

 29-5 



8.25 

 6.0 



14-75 

 17-75 

 15-5 



' All straight, unless otherwise stated. 



' Add 2 in. for breakage. 



