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 M. ospliyia (3d 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 1 

 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 vertebrae (5th character) in the type-skeleton as mounted is 48, 

 probably to be distributed as follows : C. 7, D. 1 4, 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 M. longimana. Of chevrons there 

 are 7 in position in the type of M. osphyia, with places for perhaps 10 in all. Van 

 Benedeu and Gervais give 12 as the number for M. 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 M. osphyia the breadth of the first rib on the left side is 9 in., 

 and on the right 7-J- in. In Struthers's Tay River specimen the right rib 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 M. osphyia is 135 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 M. osphyia 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 Balcenopterce ; entire width over and within 

 edge of orbit, 15^ in." This measurement I make 14 in. instead of 15^ in. The 

 former equals 10.4 % of the length of the skull. As shown in the table on p. 233, 

 the same measurement from Rudolphi's figure of the type of M. longimana is 9.0 

 %, and of Struthers's Tay River specimen 9.6 %, while the type of M. bellicosa gives 

 10.7 %. This approximation shows that M. ospliyia 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 M. 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 Strtithers's 

 Tay River whale is, according to his measurements, the same as in the types of M. 

 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 zoologists only from 



