cuvier's avhale. 563 



The larger tooth thus has a diameter of nearly one and a half 

 inches, while the part which projects beyond the gum exceeds 

 one and three-fifths inches. 



The teeth just described have a close resemblance to those of 

 the specimen from the Chatham Islands, described and figured 

 by Hector (1872, pi. v.) under the name of Epiodon chathamensis, 

 now usually regarded as a synonym of Z. cavirostris. They are 

 also precisely similar to those of a specimen. No. 21248, from 

 Bering Island, described and figured by True (1910, p. 52, 

 pi. xxii. fig. 4) and regarded by him (pp. 31, 35) as probably 

 belonging to an adult male. It is important to notice that the 

 Wexford specimen was definitely ascertained to be a male, from 

 its characters in the flesh ; and it thus confirms the accepted 

 conclusion that the teeth of Ziphius are larger and more massive 

 in the male than in the female. In the paper just cited (p. 54) 

 True states his conclusion that adult males have '' fusiform teeth 

 with closed roots and a diameter of from 25 to 30 mm.," while 

 in females they are " quite slender, with a diameter of from 10 

 to 14 mm." 



The specimen* from Unionhall, Co. Cork, was stranded on 

 Feb. 13, 1913 ; and it was described as much injured, being in 

 an advanced state of decomposition, with most of its skin worn 

 away. There are thus no observations to record with regard to 

 its colour or sex. Its length is said to have been 20 feet. The 

 lower jaw had a considerable resemblance to that of Hyperoodon ; 

 and, as there were no teeth piercing the gum, it was supposed 

 that it belonged to that genus. The examination of the skull, 

 two years later, at once corrected this mistake. The absence of 

 the large maxillary crests which are so characteristic of Hyper- 

 oodon is alone sufficient to show that it cannot belong to thtit 

 genus ; while as features specially distinctive of Ziphius and 

 possessed by this specimen, mention may be made of the peculiar 

 form of the premaxillje and the great difi'erence between those of 

 the two sides, as well as of the elongated nasals, separated from 

 one another by a long suture. The length of the skull is about 

 3 feet 3 inches; the Shetland skull described by Turner (1912, 

 p. 77) being 36^ inches long. 



In his recent elaborate account of the cranial characters of 

 Z. cavirostris, True (1910, p. 54) states his belief that the two 

 sexes of this species are distinguishable from one another by 

 certain well-marked cranial characters, in addition to those 

 afibrded by the teeth, as noted above. He admits, however, 

 tliat the sex of some of the specimens from which his conclusions 

 were drawn was not definitely known. The adult male was 

 believed to be distinguishable by the great development of the 

 " mesorostral ossification " (Turner) and by the presence of a 

 deep " prenarial basin." In the adult female the mesorostral 

 ossification is less developed, while the premaxillse are narrow, 



* For assistance in obtainiiiir the skeleton of this specimen, the Museum is i)i 

 flebted to Mr. J. Phelau, of H.M. Coastguard, Unionhall. 



