44 TRANSACTIONS OF THE WAGNER FREE 



the roof of the mouth is another capacious and deeply concave recess 

 bounded laterally by the palate bones and pterygoids. Below the bottom 

 of the orbit a cellular expansion extends backward from between the max- 

 illa and the palate bone, as in Dicotyles labiatiis, but proportionately much 

 greater. 



The roof of the mouth or hard palate is narrower than in Dicotyles 

 labiatiis, and though in general roughened, it scarcely exhibits the trans- 

 verse lateral ridges of this animal. In advance of the molar teeth it re- 

 sembles more that of D. angzdatus than of the former, and the incisive 

 foramina are larger. Its back part, from the position of the last molars, is 

 depressed into a broad cavity instead of a narrow groove as in Dicotyles 

 labiatus. 



The glenoid fossae have a more downward position than in the Pecca- 

 ries, and they are less transverse, i. e., their long diameter has a more back- 

 ward inclination. 



The mandible is nearly like that of Dicotyles. The angle is of greater 

 extent fore and aft ; is produced less backward and more downward and 

 forward. Its outer surface slopes downward and outward, while in the Pec- 

 caries it is quite vertical. Its semicircular border is decidedly everted and 

 forms a strongly projecting ridge which is but feebly produced in the latter 

 animals. 



The symphysis of the jaw, instead of forming a flat inclined plane as in 

 Dicotyles, is contracted into a prominent obtuse carina. 



The fore part of the jaw is more tapering and less robust than in Dico- 

 tyles labiatus. 



The ascending portion of the ramus of the mandible of Platygomis is 

 shorter than in the latter and is directed backward to such an extent that 

 the condyle forms the most posterior part of the jaw, whereas in Dicotyles 

 it bends forward and the angle is the most posterior part of the mandible. 

 The coronoid process is shorter than in Dicotyles labiattis, less tapering and 

 slightly inclined backward instead of forward as in the latter. 



The mandibular condyle is decidedly smaller than in Dicotyles labiatus, 

 and in comparison with that of the latter is, as it were, cut off at the inner 

 extremity. 



The formula of dentition of Platygonus is the same as in Dicotyles, and 

 the teeth have the same essential construction, but proportionately are not 

 quite so robust. 



The molar teeth in general conspicuously differ in the greater propor- 

 tionate production in length of the chief constituent lobes of the crown, 

 which appear separated by deeper and more conspicuous valleys, and they 

 are further provided with a more distinct basal ridge. In the Peccaries the 

 malars have a decided suilline aspect, but in Platygonus they assume to a 

 greater degree than in the former an ordinary ruminant likeness. 



