414 Zoological Society. 
We have in the Museum a very large and a moderate-sized skull 
of the domestic Pig, slightly differmg 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 11, 
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 sufficient 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 much 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 :— 
1. Face smooth, or nearly so; skull conical; the upper part of 
the nose rounded ; palate narrow. Svs. 
Sus scrofa, Sus indicus, Sus vittatus. 
2. Face deeply and symmetrically furrowed; the skull flattened 
on the forehead ; the upper part of the nose flattened, keeled on the 
sides; palate broad. CrNTURIOSUS. 
Sus pliciceps. 
I regard these facts as very interesting, first, as adding a new 
kind of domestic animal to our list (and I do not think that any 
has been added since the introduction of the turkey from Mexico) ; 
and secondly, as showing, from a domestic animal, that there must 
be a wild species which has not yet been brought into our cata- 
logues. 
I may observe that, like many other very distinct species of cer- 
tain genera of domesticated or semi-domesticated Mammalia, as the 
Horse, Ass, and Zebra, the Ox, the Dog, &c., the fact of inter- 
breeding is no proof that a kind is not a species; for no one would 
