776 PROFESSOR TURNER ON ZIPHIUS CAVIROSTRIS 



situated 9 inches behind the tip of the jaw, and almost on a line with the hinder 

 end of the symphysis. The length of the mandible was 27^ inches, that of its 

 symphysial portion 9| inches. The symphysis was therefore not only relatively, 

 but absolutely longer in Sowerbyi than in cavirostris. In the articulated skull 

 the lower jaw projected, as in cavirostris, beyond the tip of the beak. 



Comparison of this Skull ivith previously recorded Specimens. — Of the specific 

 identity of the skull in the Edinburgh Museum with Sowerby's original speci- 

 men, and with the crania from Havre, Calvados, Ostencl, and Christiania, I 

 have satisfied myself, by comparing it with the cast of the skull of the first, 

 and with the published figures of the last-named crania. The Irish specimens 

 also are in all probability of the same species, although, so far as I can ascertain, 

 figures of these crania have not been published. Differences, however, of a 

 very appreciable character exist between the Edinburgh skull, the exotic speci- 

 mens referred to in the historical sketch, and the skull named Dioplodou 

 europceus by Gervais. In the skull from the Seychelles Islands, to which the 

 specific name densirostris is usually applied, not only is the want of symmetry 

 more decided, but the meso-rostral canal instead of being empty is occupied by 

 an elongated slender bar of dense bone, and the mandible is thicker and deeper 

 behind the symphysis, where the mandibular pair of teeth project from their 

 alveoli. The skull from the Cape, named Layardi, also unsymmetrical, pos- 

 sesses even a more strongly marked meso-rostral bone than densi?*ostris ; the 

 mandible is not, however, thickened and deepened, but contains a pair of 

 remarkably elongated and curved teeth, which arch upwards and backwards at 

 the sides of the rostrum to meet each other superiorly. Although various 

 zoologists have proposed to give a generic value to the differences exhibited by 

 Soiverbyi, densirostris, and Layardi, and have made each the type of a distinct 

 genus, yet I agree with Owen that there is nothing in the structural characters 

 of either of the three to justify more than a specific difference. The New Zealand 

 specimen figured by Knox and Hector, though referred by Gray to the genus 

 Berardius, is without question much more closely allied to Sowerby's whale. 

 Like Sowerbyi it did not possess a meso-rostral bone, but the beak, judging 

 from the figure, was not so slender and elongated, the want of symmetry in the 

 nasal region was greater, and the pair of mandibular teeth were situated close 

 to the tip of the jaw. Some of these differences may, perhaps, be due to the 

 youth of the specimen, but the forward position of the mandibular teeth marks, 

 in all probability, a distinct species. 



In the Dioplodon europoeus of Gervais, the cranium is longer and wider than 

 in Sowerbyi; the beak also is wider, owing to the rostral part of the superior max- 

 illa? being more strongly pronounced, and the meso-rostral canal is completely 

 filled by an elongated meso-rostral bone. Moreover, the mandible is not so 

 curved at its upper and lower margins, its symph} r sis is shorter, and the single 



