254 THE WHALEBONE WHALES OF THE WESTERN NORTH ATLANTIC. 
There is, as already stated, considerable variation, the cause of which is not entirely 
clear. This variation affects the American specimens, which I have endeavored to 
measure in a uniform manner, nearly as much as the European specimens, the 
measurements of which are collected from various sources. 
The measurements of the Taranto (Italy) whale given by Gasco in the text of 
his article (47) do not agree with measurements taken from his figures, and meas- 
urements from the different figures do not agree with one another. Furthermore, 
Capellini’s measurements of the same specimen do not altogether agree with Gasco’s. 
Guldberg’s measurements of the Iceland skulls also lack conformity to a consider: 
able degree. While these differences may be partially due to different methods of 
measurement, it can hardly be supposed that they all arise in that way. This 
explanation does not serve in the case of my own measurements. 
It seems probable that the discrepancies are in part due to the shrinking and 
warping of the various bones of the skull. The long, slender maxillee and pre- 
maxille, the long orbital processes of the frontals and maville, seem quite easily 
subject to such distortion, and in some skulls it can readily be seen that warping 
has taken place. Again, it should be observed that most of the skulls are those of 
young individuals, and probably exhibit differences of proportions correlated with 
different stages of growth. Aside from all this, however, it is undoubtedly true 
that the species shows a considerable individual variation in proportions. 
The measurements of the length of rostrum in Guldberg’s skull, received from 
Capt. Amlie, and in Capt. Berg’s No. 2, are from the base of the same and not from 
the posterior margin of the maxilla, as in other cases. This accounts for the 
diminished length. The measurement of the rostrum of the Taranto whale was 
taken from Gasco’s figure of the upper surface of the skull (47, pl. 2, fig. 1); but 
it is obvious on comparing this figure with the side view that the rostrum is too 
short in the former. A measurement from the side view gives about 77.2 % for 
the length of the rostrum, which is no doubt more nearly correct. 
Gasco’s measurements of the mandible of the San Sebastian whale of 1854 
are “from the point of meeting of the internal lateral margin with the inferior 
margin of the condyle,” which accounts in part at least for the much smaller 
proportion. 
The other discrepancies, affecting the breadth of the skull across the orbits, the 
length of the mandible, and the distance along the curve of the premaxille, from 
the tip of the nasals to the tip of the premaxill, cannot be so readily explained. 
As they occur in both the American and the European series, however, they cannot 
be regarded as indicating specific differences. Doubtless, many of them would dis- 
appear if the various specimens could be brought together for actual comparison. 
CHARACTERS OF THE VERTEBRZ. 
Measurements of the vertebre and other parts of the skeleton in a few Euro- 
pean and American specimens are given in the following table: 
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