On the Skull of an aged male Hyperoodon rostratus. 19 



As regards the colour of tlie skin, my two specimens show 

 that differences occur at different ages. This probably 

 accounts for the discrepancies in the descriptions of the 

 colour markings as given by several writers. Sex also may 

 influence the colour, though probably not to the same extent 

 as age. In the young male the tip of the beak was more 

 uniformly white, though with a dash of yellow, than in tlie 

 adult female, in which it had a whitish-grey tint. In both, 

 however, a darker grey patch was present at the exact tip. 



Some light can now, I think, be thrown on the time of the 

 year when this dolpliin produces its young. The adult female 

 obtained by Dr Joass was in calf in the month of May. The 

 adult female, which I purchased in July 1888, was nursing 

 the young male caught along with her. This whale produces 

 her young, therefore, in the summer, probably in the months 

 of June and July. My young sj)ecimen is smaller than the 

 young female captured in September and described by Dr 

 Cunningham, and that again is smaller than the young male 

 described by Mr J. W. Clark, which was taken in March, and 

 the greater size of their specimens represents the growth of 

 the animal during the autumn and winter months. 



III. Notes on the Skull of an aged male Hyperoodon rostratus 

 from Shetland. By Professor Sir Wm. Turner, M.B., 

 LL.D., F.E.S. 



(Read 16tli January 1889.) 



Two years ago I communicated to the Society a paper " on 

 the occurrence of HyiKvoodon rostratus in the Scottish Seas,"^ 

 and referred to several specimens which had come under my 

 own observation. I pointed out that the specimens had been 

 almost exclusively either females or young males. Only one 

 British specimen of an adult male was, indeed, at that time 

 known, viz., a cranium in the British Museum, obtained 

 many years ago in the Orkneys, which, from the breadth of 

 the maxillary crests, it was at one time customary to name 

 Hyperoodon latifrons (J. E. Gray),^ though it is now^ known 



1 Proc. Roy. Phys. Soc, vol. ix., p. 25, 1886. 



- Zoology of Yogage o[ Erchus and Terror, p. 27, pi. 4, 1846. 



