18 Proceedings of the Uoyal Physical Society. 



The presence of a rudimentary moustache in the young 

 male white-beaked dolphin is interesting, as furnishing an 

 interesting example of a cetacean in which the hairy coat 

 characteristic of the mammalia generally, has not entirely 

 disappeared. This is not the first occasion on which hairs 

 have been seen in the white upper lip of this species. J. G. 

 Gray described ^ six bristles, and both D. J. Cunningham ^ 

 and J. W. Clark 3 have recorded the presence of four bristles 

 in each upper lip of their specimens. 



Mr Clark's example was, like mine, a young male, Dr 

 Cunningham's a young female, so that the rudimentary 

 moustache is not a characteristic of the male sex. In the 

 adult female which I examined, and in the adult specimens 

 which have been observed by other naturalists, hairs in the 

 upper lip were not seen, so that their presence is a mark of 

 immaturity in this cetacean, in which they disappear as it 

 attains adult life.* 



The length of the adult female, 8 feet 6 inches (2593 mm.), 

 establishes it as probably the longest adult female which has 

 yet been measured. Brightwell's adult female was 2490 

 mm., and Van Beneden's was 2330 mm. But several adult 

 males have been measured which exceeded it in length, as 

 appears from the following table extracted from Max Weber's 

 article^ on this dolphin : — 



Males. 

 Metres. 



Moore, . . . . 2.70 



Max Weber, .... 2.74 



A. W. Malm, . . . 2.82 



Claudius, . , . . 2.91 



Claudius, . . . . 2.99 



^ Voyage oi Erebus and Terror, p. 35, 1816. 



2 Proc. Zool. Soc, June 20, 1876. 3 /j^-^^^ 



^ In the Megaptera loncjimaiui, the anatomy of which has been so elaborately 

 described by Professor Struthers, the stiff hairs in the lower lip varied from 

 I to 1 inch in length. The animal was 40 feet long, and the vertebral ej)iphyses 

 were unossified (Jour, of Anat. and Phys., vol. xxii., pp. 119, 443). Various 

 naturalists have described a moustache in the fcetus of the following genera 

 of Delphinidfe, viz., Delphinus, Tursiops, Stcno, ZagcnorJiyncMis, Glohice- 

 phalus, Phoccena ; and Eschricht has described a moustache in the foetus of 

 JBalcenoptera rostrata and Megaptera longimana. (See M. Fischer in Melanges 

 C^tologiques — Actes dc la Soc. Linn6cnne dc Bordeaux. Nov, 1868.) 



^ Tijdschrift der Nedcrlandsche Dierkundige Vereeniging, Leiden, 1887. 



