774 PROFESSOR TURNER ON ZIPHIUS CAVIROSTRIS 



The nasal bones, about 2 inches long, were laterally compressed, almost verti- 

 cal in position, and locked in between the upper overhanging borders of the two 

 pre-maxillae, which partially concealed them. The nasal septum was mesial, so 

 that the anterior nares were symmetrical. The vertical diameter of the entire 

 orifice was 2^ inches, the greatest transverse If inch. The upper border of the 

 septum was sharp and concave ; its anterior border closed in the posterior end 

 of the meso-rostral canal, and was faintly tuberculated as if for attachment to 

 the mes-ethmoid cartilage. 



The vomer formed the floor and in part the sides of the meso-rostral canal. 

 It gradually tapered off in front, and did not reach to within 6^ inches of the 

 anterior end of the beak ; posteriorly it was prolonged along the sides and 

 inferior border of the mes-ethmoid nasal septum, with which it blended. 



The superior maxilla extended only to within 4£ inches of the tip of the 

 beak, and formed a narrow bar of bone, between which and the pre-maxilla only 

 a shallow furrow was seen. Although it expanded rapidly at the base of the 

 beak to overlap the frontal, the maxillary fossa was slight, and the surface of the 

 bone was not pitted. The maxillary foramen was not large and single, but was 

 subdivided into several smaller openings. The ecto-maxillary ridge had a sharp, 

 knife-like edge, and the maxillary tuberosity could scarcely be said even to be 

 indicated. 



The inferior surface of the beak flattened at the tip was formed by the pre- 

 maxillae : at and towards the base it was slightly convex, and consisted of the 

 superior maxillae ; but the intermediate part was faintly concave, and its sides 

 were formed of the superior maxillae, between which the pre-maxillae extended 

 backward for some distance, whilst the lower border of the vomer came to the 

 surface in the mesial line for a distance of 6| inches. 



The palatine plates of the palate bones articulated mesially for 1\ inch, and 

 then diverged in front to permit the superior maxillae to pass backward between 

 them. Each plate stretched out laterally as far as the lachrymal bone. A 

 small posterior palatine foramen was situated close to the right palato-maxillary 

 suture. The two palate bones were in part inserted between the two pterygoids, 

 which also articulated mesially with each other, and passed back to form the 

 sides and floor of the posterior orifice of the nose. Each pterygoid curved out- 

 ward from the mesial and palato-pterygoid sutures to form a ridge, which over- 

 hung the outer surface of the pterygoid, and formed a deeper fossa than was 

 seen in cavirostris — an arrangement which presented a closer approximation to 

 a posterior palatine air-sinus than was seen in that animal, though, as in it a 

 reflected plate of bone was not developed. The posterior nasal opening was 2^ 

 inches in height by 3 inches in transverse diameter. As in cavirostris, the hinder 

 edge of the vertical plate of the vomer was some distance within the opening, 

 the roof of which was formed by the expanded part of that bone, whilst a 



