42 TRANSACTIONS OF THE WAGNER FREE 



(Am. Jour. Sci., 1848, 102; Mem. Amer. Acad. Sci. and Art, 1848, 257.) 



The two skulls of Platygo?ius coinpressus, from New York, found to- 

 gether, are nearly identical in condition of age and anatomical character. 

 As exemplified by figure I, plate VIII., of the better preserv^ed specimen, 

 the skull approximates in size as well as in shape and construction that of 

 the larger South American species of Peccary, Dicotyles labiatns. It is on 

 the whole somewhat larger, and especially has the cranium of greater 

 breadth and the face considerably longer and more tapering. The temporal 

 fossae are of less extent fore and aft and have nearly the same depth and 

 width, so that they have actually less proportionate capacity and thus indi- 

 cate less powerful temporal muscles. The sagittal crest has about the same 

 extent, but the temporal ridges are shorter and are more widely divergent. 



The forehead is of much greater breadth, but proportionately shorter, 

 and it is flatter, while the supra-orbital ridges are more elevated or brought 

 nearer to the same level. Its fore part, nearly on a line with the front of 

 the orbits, slants more abruptly, and the top of the face is thence to the end 

 of the snout more convex. 



The orbits are situated more posterior and higher and are of greater 

 depth. The supra-orbital ridge is more prominent outwardly and the infra- 

 orbital ridge is everted. The entrance is more open behind and is bounded 

 in front by a larger and conspicuous conical lachrymal eminence defined by 

 deep notches. 



The supra-orbital foramina hold nearly the same relative position, but 

 are not quite so much advanced, and from them proceed conspicuous neuro- 

 vascular grooves in the same manner as in the Peccaries. 



The zygoma has the same form and construction as in Dicotyles labiatns, 

 but is of considerably greater vertical depth. Its posterior abutment with 

 the ascending angular process and relative position of the glenoid articula- 

 tion and auditory meatus is the same. The quadrate notch forming the 

 outer limit of the temporal fossa is deeper, but of less extent fore and aft. 

 The malar portion of the arch is more elevated above the temporal zygo- 

 matic process, so that the latter seems more projecting beneath and the 

 glenoid articulation appears more dependent. The outer face of the malar 

 is more vertical and is concave. 



In Dicotyles labiatus, the malar crest, forming the most prominent por- 

 tion of the skull laterally, appears as an acute ridge defining the zygoma 

 below and ascending obliquely from the glenoid articulation to near the 

 middle of the face. In Platygonus it forms a semicircular ridge defining the 

 malar below from behind the post-orbital process to the maxilla, where it is 

 continuous with a less acute ridge not extending so far as in the Peccaries. 

 The malar crest ceases above the position of the infra-orbital foramen, cor- 

 responding with that of the last premolar tooth. The surface in advance of 

 the orbit slopes as in the Peccaries, but is less depressed, and is remarkably 



