160 



ON A SKELETON OF A WHALE IN THE 



Thompson's specimen.' 7 So far as appears, Mr. Billings hall 

 never seen the Vermont specimen, at least had not studied it. 

 Dr. Whiteaves writes : " The identification of the Mile-end 

 specimen, and of that from Cornwall, with Beluga vermontana, 

 it must be remembered, is solely on the authority of Mr. Bill- 

 ings. It seems to me that the specimens from those two local- 

 ities and the skull, etc., from Pakenhain, which are all that I 

 have seen, are at any rate all referable to the same species. A'nd 

 I do not see how they are to be distinguished from the present 

 D. leucas!' 



The question whether the Vermont specimen is as Thomp- 

 son decided, a new species or leucas. has usually been decided 

 by writers in favor of the living species. Thompson's reasons 

 for .separating it from leucas were, a difference in dentition, in 

 size of maxillary bones and some minor points. None of these 

 are sufficient, considering the individual variation within the 

 same species of many cetacea. As has been previously noticed, 

 the periotic is less likely to vary in different individuals of the 

 same species than any other bone. After a study of this bone v , 

 Mr. Andrews writes, " 1 have compared the bone with the ear- 

 bones of several specimens of Delphinapierus leucas. The 

 resemblance, except in size, is very close indeed. The bullate 

 portio'n of the periotic in your specimen is somewhat smaller in 

 proportion to the whole length than in Delpliinapterus leucas. 

 The internal auditory meatus is also slightly different in shape. 

 However, I believe that these characters are open to a slight 

 individual variation. The difference in size seems to ine an 

 important one, as it probably indicates that your animal, if 

 adult, is a smaller animal than Delpliinapterus leucas. A com- 

 parison with the periotic of a very young individual of Delpliin- 

 apterus leucas shows this bone in the latter to be considerably 

 larger than in your specimen." 



The author visited the American Museum, New York, twice 

 for the purpose of comparing the fossil bo'nes with those of 

 recent skeletons, and then went to the National Museum, Wash- 



