768 PROFESSOR TURNER ON" ZIPHIUS CAVIROSTRIS 



symphysis, that on the lower border was altogether behind the symphysis. The 

 anterior half of the upper border was marked by a shallow groove, as if for the 

 lodgment of rudimentary teeth, though none were found in the specimen. 

 Quite at the anterior end of the bone, on each side of the symphysis, was a large 

 alveolus, about three-fourths of an inch in diameter, in which at one time the 

 large mandibular tooth had undoubtedly been lodged, but this socket was now 

 occupied by coarsely spiculated bone. The length of the mandible was 32^ 

 inches ; the length of the symphysis, 7 inches ; the width between the articular 

 condyles, inside measurement, 17 inches. The condyle was situated about the 

 middle of the posterior border of the bone. When articulated with the skull, 

 the lower jaw projected so far beyond the rostrum that the mandibular teeth 

 would, if present, have been altogether in front of the beak. 



Comparison of the Shetland Ziphius with previously recorded Specimens. — I 

 propose now to compare the Shetland cranium with the figures and descrip- 

 tions which have been published of four of the five European,* and the three 

 exotic specimens referred to in the historical introduction, with the object 

 of determining whether they represent different genera, or whether they belong 

 to one or more species of the genus Ziphius. In their general configuration all 

 the skulls closely correspond with each other, but as the peculiarly constructed 

 beak and the pre-nasal fossa with the bones which form its boundaries con- 

 stitute the most distinctive features of these crania, my attention has more 

 especially been directed to a comparison of the forms and relations of the bones 

 which enter into their construction. 



In my description I have named the dense, solid bar in the middle of the 

 beak the meso-rostral bone. This bar corresponds with the " vomer" of Cuvier, 

 Gervais, and Gray, with the " anterior tuberosity of the vomer" of Fischer, 

 with the " continuation of the pre-frontals forward to near the end of the pre- 

 maxillaries " of OwEN,t and with the " anterior prolongation of the ethmoid " 

 of Flower. \ Whatever name be applied to it, there can be no doubt that it is 

 an ossification of the anterior end of the long cartilaginous bar, which in the 

 cetacea is prolonged forwards to the end of the beak, and in relation to the sides 

 and lower surface of which the spout-like vomer is formed. In the specimens 

 recorded by Cuvier, Fischer, Doumet, Van Beneden, and Gray and Owen, 

 the meso-rostral bar, as in my Shetland specimen, was strongly pronounced. 

 Slight differences do, however, undoubtedly exist in the shape of this bone in 

 these crania. In those described by Fischer, Gray and Owen, and myself, the 

 posterior end is a little more truncated than in those recorded by Cuvier, 



* No figure or description of the Villa Eranca specimen in the Jena Museum, so far as I can 

 ascertain, has yet been published. 



t Report of British Association, 1846, p. 226, and British Fossil Cetacea of the Red Crag, p. 27. 

 % Introduction to the Osteology of the Mammalia, p. 191. London, 1870. 



