44 Proceedings of the Royal Physical Society. 



skull of the adult female Hypcrooclon captured at Alloa, in the 

 Anatomical Museum of the University of Edinburgh^ as, from 

 the form of its skull, a specimen of H. iatifrons. In a corre- 

 spondence which I had with Mr Thomas Southwell, of N'orwich, 

 some time ago about this specimen, I stated to him that it did 

 not possess the broad lofty crests which Dr Gray gave as tlie 

 specific mark of H. Iatifrons, so that, as Mr Southwell very 

 properly has pointed out, the only instance adduced by Dr 

 Gray in favour of his new genus, in which the sex was said 

 to have been noted in the flesh, is disposed of.^ I can give 

 no explanation of how Dr Gray came to regard the specimen 

 from Alloa as like the Orkney skull with the broad and 

 lofty maxillary crests, for, so far as I know, its skeleton has 

 not been described, and a mere glance at the specimen would 

 satisfy any one, that in its entire configuration, it resembled 

 the usual figures of the skull of H. rostratus. 



But the question of the specific distinctness of H. Iatifrons 

 has recently been set at rest by the observations of the enter- 

 prising whaling seaman, Captain David Gray, who has 

 especially applied himself to the capture of Hypcrooclon for 

 commercial purposes.^ From the large number of specimens 

 which he has killed, of both sexes and of various aoes, he has 

 been able to show that the skulls with narrow maxillary 

 crests are those either of females or young males ; and he 

 has traced the gradation from the low and narrow crest of a 

 young male through various stages of broadening and height- 

 ening, until the very broad and lofty crests of the so-called 

 H. Iatifrons had been reached. There is no longer, therefore, 

 any doubt that the broad-crested animal is the old bull of 

 H. rostratus, and that the development of these crests gives 



' Trans. Norfolk and Norwich Naturalists' Soc, vol. iii,, p. 476, At the 

 time when I had the correspondence with Mr Southwell, I had not read Mr 

 Wni. Thomi^son's Paper in the Annals of Natural History, March 1846. Had I 

 done so, I should have been able to have rectified at that time the date of the 

 capture of the Alloa specimen, which, as stated in the text (p. 30), was 

 1845 and not 1839, as is so often named by Dr Gray. 



^ Proc. Zool. Soc, London, Dec. 19, 1882. Also Professor Flower's Paper 

 in the Proceedings of that Society of the same date ; and Mr Southwell's 

 Article of the same date in Trans. Norfolk and Norwich Naturalists' Society, 

 voL iii., p. 476. 



