242 THE WHALEBONE WHALES OF THE WESTERN NORTH ATLANTIC. 
I have already shown that the 4th and 7th characters are fictitious, as advanced 
by Cope, and that the 1st is merely an individual variation. 
The width of the cranium of the type of JZ osphyia (8d character) as com- 
pared with the length, differs from that in the Scotch skulls carefully measured by 
Struthers by only 1.1 per cent., which in actual measurement amounts to only 14 
inches. This is certainly not significant, and is within the limit of variation of 
different American specimens of the Humpback among themselves. 
The number of vertebra (5th character) in the type-skeleton as mounted is 48, 
probably to be distributed as follows: C. 7, D. 14, L. 10, Ca. 17 (+-) = (48 +). The 
last vertebra present is 4 in. square, and according to Struthers’s measurements of 
M. longimana, about 4 more caudals must have been present originally, making 52 
for the whole column, which is the average for JZ. longimana. Of chevrons there 
are 7 in position in the type of J. osphyia, with places for perhaps 10 in all. Van 
Beneden and Gervais give 12 as the number for JZ. longimana, but it is to be 
remarked that Struthers’s Tay River (Scotland) specimen had but 10 chevrons, 
and the skeleton in the National Museum (No. 16252) from Cape Cod, Mass., but 
9, so that it would appear that the number is variable, and unreliable as a specific 
character. 
In the type of JZ. osphyia the breadth of the first rib on the left side is 9 in., 
and on the right 74 in. In Struthers’s Tay River specimen the night rb of the first 
pair has a maximum breadth of 8.6 in., and the left, 5.3 in. It is obvious that the 
breadth is so variable even on the two sides of the same skeleton that it is useless 
as a specific character, but in this instance, as the skull of Struthers’s specimen is but 
125 in. long, while that of JZ. osphyza is 1385 in. long, the maximum breadth of the 
first ribs in the two skeletons is practically the same relatively, with a little increase 
in favor of the European specimens. 
In 1868 Cope cited as an additional character of M7. osphyca the contraction of 
the orbital process of the frontal at the distal extremity (27, 194). He remarks: 
“The orbital processes of the frontal bone are not contracted at the extremities as 
in M. longimana, but are more as in Balenoptere ; entire width over and within 
edge of orbit, 15} in.” This measurement I make 14 in. instead of 155 in. The 
former equals 10.4 % of the length of the skull. As shown in the table on p. 288, 
the same measurement from Rudolphi’s figure of the type of JZ. longimana is 9.0 
%, and of Struthers’s Tay River specimen 9.6 %, while the type of J/. bellicosa gives 
10.7 % This approximation shows that J/. osphyia presents no great deviation in 
the breadth of the supraorbital edge of the frontal. It is true that in Rudolphi’s 
figure of the whole skeleton of the type of J. longimana the orbit itself appears 
smaller, but in a general figure of this kind the proportions of the smaller parts are 
frequently inaccurate. The least longitudinal diameter of the orbit in Struthers’s 
Tay River whale is, according to his measurements, the same as in the types of AZ. 
osphyia and M., bellicosa, As it is extremely unlikely that the two European skele- 
tons belong to different species, the probability that Rudolphi’s figure is inaccurate 
as regards the orbit is strengthened by this circumstance. 
The Humpback appears to have been known to European zodlogists only from 
