470 DR. J. V. HAAST ON ZIPHIUS NOViE-ZEALANDI^E. [June 6, 



to a skull of larger dimensions than the one obtained from the 

 Chatham Islands, described by Dr. Hector, is scarcely the fourth of 

 the weight of the tooth of the latter. It is moreover evident that 

 the teeth of the Chatham-Island specimen must have been used, as, 

 according to the description, they are worn down into two lateral facets, 

 divided by an acute ridge (see 'Transactions New-Zealand Institute,' 

 vol. v. page 165), whilst in the New-Zealand specimen the tips are 

 as rough as the sides and roots and do not show the least sign of 

 wear. 



We know that the two skulls of the New-Zealand specimens belong 

 to female skeletons, whilst the skull of the Chatham-Island specimen 

 may possibly have been that of a male ; but as we have not the least 

 evidence in that respect, this can only be settled by future researches 

 into the anatomical characters of this interesting genus. 



Returning to the skeleton under consideration, I wish to state that 

 the teeth were only visible after maceration, and appear to be alto- 

 gether functionless, because the lower jaw projects so much beyond 

 the rostrum — unless we assume that the whole had an upper lip of a 

 somewhat prehensile character. On the upper margin all along the 

 anterior half of each ramus a well-defined groove extends to the dental 

 canal at the anterior extremity, where it is broadest. A considerable 

 number of small vascular canals open into this groove, without, how- 

 ever, showing the least rudiment of teeth. 



The coronoid process is marked very feebly ; but the condyle is well 

 developed and forms the most posterior portion of the bone. I may 

 here observe that the skull of Ziphius novae- zealandice resembles in 

 some respects that of Ziphius australis of South America, notwith- 

 standing the difference in the form of the head, the former having a 

 swollen, and the latter having a tapering forehead. In many instances 

 Prof. Burmeister's excellent description of some of its osteological 

 characters could be applied quite well to the New-Zealand species. 



Hyoid bones. 



The basihyal and the thyrohyals are still unankylosed, notwith- 

 standing the great age of the animal. The former has a somewhat 

 trapezoidal form, thus resembling in that respect the same bone in 

 Ziphius australis ; but it is more pointed in its anterior portion and 

 has a deep notch in the centre, whilst in the South-American species 

 the anterior border is only slightly concave. Breadth 4*6 inches, 

 antero-posterior length on both sides of the notch 4*1 inches. The 

 thyrohyals have a length of (r80 inches, with their greatest breadth 

 of 2*55 inches one third from their posterior end. 



The stylohyals are 10*8 inches long, and, in their middle portion, 

 2* 1 inches broad ; they are straighter than the same bone in Ziphius 

 australis, which they resemble, however, otherwise in form. The 

 whole apparatus is more slender than in the Buenos-Aires species. 



Vertebral Column. 

 The following are the numbers of vertebrae : — 



