THE WHALEBONE WHALES OF THE WESTERN NORTH ATLANTIC. 295 
In spite of the correspondence in general proportions between two Pacific 
skulls and the Norway and Massachusetts skulls, my associates, Dr. L. Stejneger 
and Mr. G. 8. Miller, Jr., who examined them with me, while side by side in one of 
the halls of the Museum, pointed out certain characters in which the two Atlantic 
skulls appeared to them to differ from the two Pacific skulls. The principal of 
these were (1) that the nasal processes of the maxille were bent toward the median 
line much more strongly in the Pacific than in the Atlantic skulls, and (2) that the 
orbital process of the maxillee was shorter and thicker in the former than in the 
latter. The characters will be seen by comparing the figures on plates 22 and 23. 
I also noted that in the Pacific skulls the vomer appeared to descend more opposite 
the anterior end of the palatines, giving a stronger curve to the inferior profile of 
the cranium, and that the palatines were broader posteriorly. I have endeavored 
to bring out some of these differences in the last three measurements of the fore- 
going table. These measurements reduced to percentages of the total length of 
the skull are repeated below : 
BALAGNOPTERA ACUTO-ROSTRATA LAC, AND B. DAVIDSONI SCAMMON. SKULL. 
ae |S ies, Wen 
FS a Ween ee ilies 
Measurement Waa eee LA nas 
i SoS Salma Pa psa 
wk Se, Sei | was 
Sx is = 5 i) a 
S See 
a H Lal Ke} 
: in in. in in 
Wotalalenothwoneskullstraicbitirayyes se sence slaetereseieys «eho orate 43:5 | 60.5 || 69.5 | 61.25 ° 
: ; : é & % :% % 
Distance from inferior surface of vomer at ant. end of palatines to 
VETLEKAE SUV ATOU in eye icnavstesatacs.o tele oustels Sholetel si sie eset one whoo BAS || Bag || Aspin || Baa 
Inner edge of proximal end of nasal process of maxilla to distal end 
offornbitalsprocess/ormaxilla straighten sete rere er cies ANS || POR || Beg} || Boe 
Outer edge of premaxilla to distal end of orbital process of maxilla, 
SLT INE Peper seokoy nach syeuny ot dhasie eCah sey ets; shayofovaeesy sl sietereioecsbercua are svererers Be) || WO || Here) || Abas 
It would appear from the foregoing that the vomer is deeper in the Pacific 
skulls, but the proportional length of the orbital process of the maxilla does not 
differ materially in the Norway and Pacific skulls. The breadth of this process, as 
shown by plates 22 and 23, is greater in the Pacific skulls than in the one from 
Norway. This greater breadth, however, is approximated in Eschricht’s figure of 
an adult skull from Norway (37, pl. 9, fig. 1). 
If any of these differences prove constant on examination of a larger number 
of specimens, it will probably be the greater depth of the vomer and the bend- 
ing inward of the nasal process of the maxilla. As regards the latter, Eschricht’s 
and Capellini’s figures of European skulls present a substantial agreement with our 
skulls from Norway and Massachusetts. 
‘Type of B. davidson. *2 in. added for breakage. 
