976 THE JOHN DAY FAUNA. 



There are two areas of insertion on the basioccipital bone, separated 

 by a low median keel, and extending anteriorly as far as the front of the 

 otic bulla. Each is interrupted in front of the middle by a rugosity. Basi- 

 sphenoid flat. The otic bullae fit the adjacent bones closely, so as to close 

 everything but the foramina. The pterygoid alae are well produced down- 

 wards. The palate of Dinictis Cyclops is flat ; and is, at the widest part, as 

 wide as long. The posterior border of the palate forms two concavities, 

 uniting medially in a slight angle. Thus the form is that of the lynx and 

 the leopard, and different from the panther, tiger, and jaguar. The forms 

 of the palates of these animals are as follows : 



I. Two deep excavations separated by a point: Moplophoneus oreodontis ; and if. 



cerebralis. 



II. Two shallow excavations, separated by an angle: Felis domestica; Unciapardus; 



Lynxrufus; Moplophoneus oreodontis ; Dinictis cy clops ; Procelurus julieni. 



III. A regular shallow concavity: Archcelurus debilis ; Uncia tigris. 



IV. A deeply excavated concavity : Uncia concolor. 



V. A triple concavity ; two lateral, separated by a deep median notch : Uncia onea. 



The mandible is compressed, but is rather low at the front of the 

 masseteric fossa. It is more robust than in the known species of Archcelurus 

 and Nimravus. The inferior anterior flange is well marked and compressed. 

 It is short, but not so broadly rounded as in D. squalidens. The anterior 

 symphysial face is flat and deep, and the incisive border elevated. 



Sutures. — The frontomaxillary suture rises from the anterior border of 

 the orbit, and then extends, with some irregularity, horizontally to the 

 frontonasal suture, as described by Leidy in the D. felina, and not descend- 

 ing, as in Nimravus hracliyops. The lateral nasal sutures are very little 

 convex outwards posteriorly, and form a segment of a circle posteriorly. 

 The frontoparietal suture is obliterated, but the superior squamosal suture 

 does not reach it. The premaxillo-maxillary suture of the palate incloses a 

 triangular space. 



Foramina. — The foramen infraorhitale exterius is very large, is subtrian- 

 gular, and is directed forwards. Its posterior border is above the anterior 

 border of the superior sectorial tooth. The incisive foramina extend to a 

 point a little behind the middles of the superior canines. The / / palatina 

 are opposite the cusp of the third premolar. There is no alisphenoid fora- 



