16 DR. J. E. GRAY ON THE JAPANESE PIG. [Jan. 28, 



that of the common domestic Pig, in being shorter, and much higher 

 in front, especially from the greater height of the front of the lower 

 jaw at the gonyx ; in the forehead of the skull being rather concave 

 before the orbits, flattened, and furnished with a sharp-keeled edge 

 on each side, producing a deep concavity on each cheek in front of 

 the orbit ; in the palate being much broader for its length, and the 

 series of the teeth wider apart and rather arched. 



In the height of the front of the skull, in the flatness of the 

 nose in front of the orbit, in the concavity of the cheek, and in the 

 broadness of the palate, the skull of the Japanese Pig bears some 

 relation to the skull of the Potamochcerus penicillatus ; but the late- 

 ral ridges of the nose are not so dilated, while the skull is higher in 

 front, and the palate is wider in the Japanese Pig than in the same 

 parts oi Potamochosrns. 



In the wild Pigs of Europe, India, and Java, and in the European 

 domestic varieties, the nose of the skull is always narrow and rounded 

 on the sides, and the palate is narrow. 



Under these circumstances, I am induced to regard the Japanese 

 Pig as a distinct type, and propose to call it Sus pliciceps until we 

 receive further information respecting it. 



We have in the Museum a very large and a moderate-sized skull 

 of the domestic Pig, slightly differing from the others, and from 

 those figured by Cuvier and De Blainville, in the frontal bone being 

 rather depressed and concave in front of the eyes ; but we do not 

 know the particular variety to which these skulls belong. Though 

 they agree with the Japanese Pig in these two circumstances, they 

 differ from it and resemble the skulls of the common Pigs and the 

 Wild Boars of Europe and Asia in all other particulars, and show no 

 other character in common with the Japanese Pig, which is also 

 characterized by its peculiarly wrinkled face, well represented in the 

 figures of these animals published in the * Proceedings of the Zoolo- 

 gical Society ' 1861, p. 263, and the * Illustrated News ' January 1 1, 

 1862, p. 49. 



The species at present is only known in its domesticated state. 

 It may perhaps be the descendant of a species found wild in the 

 valleys of the islands. 



In both these skulls of the domestic Pigs the lower jaws are rather 

 higher than usual, particularly at the gonyx ; and this is especially 

 the case with the largest skull, which is said to be that of an old 

 Boar. Can the size of the lower jaw be a peculiarity of the male sex ? 

 We have not sufiicient materials to determine this question, either in 

 the Museum or in the plates that have been published of the skull 

 of the genus Sus. 



I may further observe, there is considerable difference in the occi- 

 put between the European and the Japanese Pig ; the processes of 

 the back of the palate are mucli more erect in the Japanese Pig 

 than in the European and Asiatic Pigs, wild and domesticated. 



Though I have only described this animal as a species, it evidently 

 forms a section in the genus by itself. The restricted genus Sus 

 may be divided thus : — 



