204 THE WHALEBONE WHALES OF THE WESTERN NORTH ATLANTIC. 
BALAINOPTERA ACUTO-ROSTRATA LAC. EUROPEAN AND AMERICAN. SCAPULA. 
: Length of Skull Percentage of Bread Per Depth 
Locality. a of Seen a Seaaoe aie ne 
Drogheda, Ireland...... 37.0 31.8 20.3 
Miasss(UiiSs Ne Vis) seer 43-5 33-9 20.7 
Norway (U.S. N. M.)... 60.5 39.8 22.8 
Bea crcoeno Om hare Cran, 62.5 37.6 22.4 
Cromer, England........ 65.0 40.8 DB 
Granton, Scotland...... 70.0 42.9 22.9 
The Norwegian skeleton in the National Museum is the only one which 
breaks the regular gradation. 
The scapula of B. acuto-rostrata appears to have been seldom figured. Esch- 
richt’s figure, copied above, is not very satisfactory, and the figure in the Ostéo- 
graphie appears distorted. Outlines of these figures and of the scapule of the 
Massachusetts and Norway specimens in the National Museum are shown in text 
figs. 58 to 56. The scapule of the last two are also figured on pl. 27, figs. 3 and 4. 
In respect of number of phalanges the skeletons preserved in museums are 
usually defective, and no accurate comparisons can be made. ‘The numbers derived 
from examination of foetal specimens are far more satisfactory, but the two series 
are, of course, hardly comparable. The enumerations of various cetologists for B. 
acuto-rostrata are as follows: 
BALZZNOPTERA ACUTO-ROSTRATA LAC. EUROPEAN. PHALANGES. 
Phalanges. 
Locality. Age. SS SSS eee Authority. 
II III. IV V 
Bergen, Norway....... | Ad 4 7 6 3 Lilljeborg 
. poe ka Akers lh favsratetets ate 3 7 6 3 ae 
my SEA Meveerommatsg|/ tofsroretepere 4 6 5 3 Fischer 
s Sond. Sede escort ie 5 8 7 4 Malm 
: Se aha a 4(+ 1) 8 7 r (+ ?) s 
AR AER ep ene Embryo 4 9 8 4 Kiikenthal 
a 4 9 7(8)| 4 “ 
Datta gieraxend Rpebevorcteritar || an svaxencnrerote 3 7 6 Nes | Eschricht 
FEE en Nas eect Ba coe TIONG 0 3 (4) 7 6 3 Weber 
| 
For the skeleton from the coast of Massachusetts, No. 20931, which is that of a 
young animal, the formula is as follows : Left, 3. 6. 6. 0 +. ; right, 2 4-. 7.5 (+1). 1+. 
STERNUM. 
The sternum of the Massachusetts skeleton has not at all the Latin-cross form 
characteristic of adult specimens of B. acuto-rostrata, but it represents, doubtless, 
an immature stage leading up to that form. The anterior moiety is short and 
broad, with a rounded contour; on each side is a tubercle, or rudimentary arm ; 
