ON A SPECIMEN OF THE SOUTHERN BOTTLE- 

 NOSED WHALE, HYPEROODON PLANIFRONS 



By F. C. Fraser, D.Sc. 

 Department of Zoology, British Museum (Natural History) 



(Text-figs, i-ii) 



INTRODUCTION 



THE specimens of Hyperoodon planifrons, the Southern Bottlenosed Whale, of which there are 

 published accounts, are few enough in number to be detailed. The type of the species in the 

 British Museum collection is an imperfect, partly waterworn skull (Reg. no. 1814A) from Lewis 

 Island, Dampier Archipelago, North- Western Austraha, described and figured by Flower in the 

 Proceedmgs of the Zoological Society (1882). In the Anales del Museo de la Plata (1895), F. P. Moreno 

 gives a brief account of three specimens : 



(i) Skeleton of an adult from the coast of the province of Buenos Aires. 



(2) Skull of an adult, Chubut Territory, Patagonia. 



(3) Skeleton of a young animal, Santa Cruz Bay, Patagonia. 



Finally, the Records of the South Australian Museum, vol. iv, no. 3, 1931, contains an account by 

 H. M. Hale of a male which stranded near Port Victoria, Yorke Peninsula, South Australia. 



The present paper is concerned with the description of a skeleton from South Georgia, presented 

 to the British Museum (N.H.) by the Discovery Committee, with an appended note about two 

 additional specimens, no part of which has been preserved, from South Georgia and the South 

 Orkneys respectively, in the Falkland Islands Dependencies. 



The widely separated regions from which the Southern Bottlenose has been recorded indicate the 

 great area of distribution of this species. It may be presumed that its range includes the Southern 

 Ocean generally and extends into the warmer parts of adjacent seas in the southern hemisphere. 



The Discovery skeleton (Reg. no. 1934.7.23 .3) belonged to an animal 6-5 m. long, a female, which 

 was presented to the Discovery Committee by Capt. Sorlle, Westfold Whaling Co., Stromness, South 

 Georgia. 



The skull and axial skeleton are in very good condition and almost complete, only the slender 

 zygomatic arches in the skull, one or two of the terminal bones in the caudal series of vertebrae and 

 probably one chevron being lacking. The appendicular portions of the skeleton are missing except 

 the scapulae which are damaged. 



The sutures of the skulls of the Discovery specimen are all well defined and the epiphyses throughout 

 the length of the vertebral column are not fused to the centra. In the South Australian specimen, 

 which was only 0-4 m. larger. Hale states that the sutures of the skull are more or less ankylosed, and 

 the figured vertebrae show no trace of separate epiphyses. These features suggest that, unlike the 

 northern H. rostratus, in which the physically mature female is appreciably smaller than the male, 

 in H. planifrons the two sexes must be about the same size when fully grown. 



Recorded dimensions of skulls of //. planifrons, together with the dimensions of a skull of H. rostratus 

 for comparison, are given in Table i. 



LATERAL VIEW OF SKULL (Fig. i) 

 In the description of the type specimen Flower (1882) drew attention to two features distinguishing 

 H. planifrons from H. rostratus, both of which are most obvious in the lateral view of the skull. The 

 first, the character which gives H. planifrons its specific name, is the relatively low development of 



