AND MESOPLODON SOWEBBYI. 705 



of the nose, and, so far as the state of the sutures allowed me to judge, the pre- 

 maxilla seemed to be directly anchylosecl to the nasal bones. 



The inferior surface of the beak, triangular in its general outline, was convex 

 from side to side, and the convexity gradually increased from before backwards. 

 The tip consisted of the two pre-maxillse, behind which the superior maxillae 

 formed this surface of the beak, except in the mesial line, where a narrow bar 

 of bone — the lower edge of the vomer, nearly 10 inches long — came to the sur- 

 face of the palate. No definite anterior palatine foramen was seen, but a distinct 

 posterior palatine canal was situated on each side at the articulation of the 

 superior maxilla and palate bones. 



The palatine plate of the palate bone was little more than 1 inch in antero- 

 posterior diameter at its widest part. The anterior margin was convex, and as 

 the superior maxillae extended backwards for some distance between the two 

 palate bones, the latter only articulated with each other in the mesial line for 

 about 1| inch. Laterally each palate bone extended backwards and outwards 

 as far as the lachrymal, a thin scale of the superior maxilla intervening between 

 it and the malar. 



The two palate bones were inserted between the anterior borders of the 

 pterygoids, which bones articulated with each other for 7 inches in the mesial 

 line of the under surface of the skull, and formed on each side of this line a 

 well-marked curved ridge, which extended as far back as the posterior orifice 

 of the nose. This orifice was bounded below and at the sides by the two ptery- 

 goids, and above by the expanded part of the vomer, the latter of which articu- 

 lated by the margins of its expanded part with the base of the pterygoids. The 

 vertical and transverse diameters of this orifice were almost equal — between 5 

 and 6 inches. Owing to the great backward development of the pterygoids, 

 the thick posterior edge of the vertical plate of the vomer, forming the 

 nasal septum, was 5f inches in front of the posterior margin of the palatal 

 plates of the pterygoids. The vertical plate of the vomer was in the mesial 

 plane, so that the want of symmetry displayed at the anterior nares did not exist 

 at the posterior nostrils. Deeply within the nose a narrow bar of the palate bone 

 could be seen on each side, intercalated between the pterygoid and the side of the 

 vomer. The outer surface of the pterygoid was hollowed into a very shallow fossa, 

 which was not, however, closed in front and externally by a reflected plate of 

 bone, to form a posterior palatine air sinus, as in Globio-cepkalus and most 

 other cetaceans. 



Behind the expanded part of the vomer the basis cranii, deeply concave 

 from side to side, owing to the lateral elevations of the basi-occipital, extended 

 backwards to the foramen magnum. All trace of the suture between the basi- 

 sphenoid and basi-occipital had disappeared, and the anchylosis of the various 

 elements of the occipital bone with each other was perfect. 



