172 SUS-STUDIES. 



foramen infraorhitale^ Sus verrucosus is distingnished hy 

 having constantly on each maxilla two foramina infraorbitalia, 

 a remarkable peculiarity till now however overlooked as 

 far as I am aware. The above described shape of malar, 

 lacrymal and maxilla give that part of the skull a much 

 broader appearance, very much less elegant compared with 

 Sus barbatus. The premaxilla bones stop close to the upper 

 incisors; these bones on the whole are much shorter than 

 in barbatus and therefore essentially contribute to the short- 

 ness of the skull. The bony palate extends posteriorly 

 perhaps still more backwards than in S. barbatus^ not- 

 withstanding it makes the impression of being a good deal 

 shorter ; this however really is not so, but a result of a 

 removing backwards of the whole molar-series, so that in 

 verrucosus the hind-most upper molar is situated exactly 

 under the two infraorbital foramina (in barbatus the anterior 

 molar is to be found under the infraorbital foramen) and 

 the posterior margin of the last molar lies in verrucosus 

 in a line with the anterior margin of the bony eye-hole 

 and about one centimeter in a straight line under the 

 posterior bow of the bony palate (in barbatus the posterior 

 margin of the hindmost molar lies a good deal anterior 

 of the bony eye-hole, meanwhile the distance between that 

 hindmolar and the end of the bony palate measured in a 

 straight line amounts to about fi-ve centimeters). 



A comparative study of the skulls of barbatus and verru- 

 cosus learns that practically there are no corresponding 

 bones of the same size or shape in the two species, so 

 that the differences may be called infinite. Very conspicuous 

 is the nearly straight profile line, nay in adult skulls, the 

 enormously developed horns of the palatine-bone and the 

 small bony eye-holes in verrucosus, and the widely separated 

 rami of the lower jaw in barbatus. 



The most interesting is the very large last molar, espe- 

 cially the last molar in the lower jaw of verrucosus; it 

 measures in the figured and here described skull not less 

 than 45 cm., in the upper jaw 40 cm., and that notwith- 



JN'otes from the Leyden ]Museuixi, Vol. XXVI. 



