318 MR. T. ATTHEY OX AXTHRACOSATJRUS ETISSELLI. 



The left maxilla. — The same force which separated and dis- 

 placed the rami of the mandible has also transferred this maxillary 

 bone to the right margin of the skull, on which it lies imbedded 

 in the matrix, with its anterior end overlying for a short distance 

 the posterior upper border of the right mandible. Ten and a 

 half inches of its inner surface are exposed ; and about an inch 

 of its anterior end is wanting. It contains twenty-eight teeth, 

 nearly all entire, and about half an inch long. They decrease 

 slightly in length backwards, and are irregularly disposed in the 

 jaw. - 



The palate-bones are about nine inches long; a transverse 

 suture divides each into two nearly equal parts. The anterior 

 borders of the foremost pieces form the posterior margins of the 

 channels leading from the external nasal orifices, and are bounded 

 internally by the vomers, and externally by the maxillaries. 

 These anterior pieces have implanted in them the large palatine 

 tusks : that on the right side is covered, as before noticed, by the 

 angular bone of the right mandible ; and that on the left side is 

 broken off at six-tenths of an inch above its large expanded base, 

 and is six-tenths of an inch thick. Behind this, on each side, is 

 a large depression nearly an inch in diameter, analogous to that 

 existing in the vomerine bones of Loxomma. 



These depressions have been noticed by Professor Huxley 

 (" Quart. Journ. Geol. Soc," Yol. XIX., p. 58, 1863), as the 

 posterior nares. The posterior pieces or halves of the palate - 

 bone, four inches and a half long, with an average breadth of 

 one inch, are sutured inwardly and backwardly to the pterygoids 

 and outwardly to the maxillaries. At an inch behind the trans- 

 verse palatine suture is a deep depression, one inch long by half 

 an inch broad, at a short distance behind which the outer margin 

 of the bone is raised up into an alveolus one inch and a quarter 

 long, containing seven closely-set teeth. The first, fifth, sixth, 

 and seventh are all broken off at their apices ; the second, third, 

 and fourth are perfect, and measure half an inch in length. The 

 last inch of the bone bears no teeth. The whole surface of the 

 palate-bones is deeply pitted, instead of being tuberculated like 

 the vomers, as has already been said. 



