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VI. On the recent Ziphioid Whales, ivith a Description of the Skeleton of Berardius 

 arnouxi. By William Hexry Flower, F.R.S., V.P.Z.S., Hunterian Professor 

 of Comparative Anatomy, and Conservator of the Museum of the Royal College 

 of Surgeons. 



B«ad November Tth, 1871. 



[Plates XXVII., XXVIII., XXIX.] 



The interest which attaches itself to the remarkable dinsion of the Cetacea which 

 forms the subject of the present communication, is in some respects even greater than 

 that which belongs to all the other members of the order. 



The Ziphioid Whales form a very compact group, closely united together by the 

 common possession of very definite structural characters, and as distinctly separated 

 from all other groups by equally definite characters. 



With the singular exception of Hyperoodon rostratus (the structure and habits of 

 which species are as well known perhaps as those of any other Cetacean), no specimen 

 of the group had ever come under the notice of any naturalist up to the commencement 

 of the present century. Since that time, however, at irregular intervals, in various 

 and most distant parts of the world, solitary individuals have been caught or stranded, 

 now amounting to about thirty, which by some naturalists are referred to upwards of 

 a dozen distinct species, and to very nearly as many genera. No case is recorded of 

 more than one of these animals having been observed in one place at a time ; and their 

 habits are almost absolutely unknown. Their very presence in the ocean seems to pass 

 unnoticed and unsuspected by voyagers, and even by those whose special occupation is 

 the pursuit and capture of various better knovra and more abundant cetaceans, until 

 one of the accidental occurrences just alluded to reveals the existence of forms of animal 

 life of considerable magnitude (for they range between fifteen and thirty feet in length), 

 and at least suflaciently numerous to maintain the continuity of the race. 



This comparative rarity at the present epoch contrasts greatly vrith what once obtained 

 on the earth, especially in the period of the deposition of the Crag formations, and leads 

 to the belief that the existing Ziphioids are the survivors of an ancient family which 

 once played a far more important part than now among the Cetacean inhabitants of the 

 ocean, but which have been gradually replaced by other forms, and are themselves pro- 

 bably destined ere long to share the fate of their once numerous allies or progenitors. 



These considerations are sufiicient to lead to the endeavour to collect all available 

 information with regard to them, and to put it in a convenient form for the guidance 

 of those who may have opportunities to pursue their history further. Doubtless such 



VOL. VIII. — PART III. September, 1872. 2h 



