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Show 470 DR. J. V. HAAST ON ZIPHIUS NOViE-ZEALANDI^. [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. W e 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 altogether 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, however, 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 nova-zealandia resembles in some respects that of Ziphius australis of South America, notwithstanding 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, notwithstanding 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 6*80 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 :- |
