370 NOTES ON THE CANID.E OF THE WHITE RIVEK OLIGOCENE. 



than in Daphcenus. In some specimens, even aged ones, the anterior half of the parietals 

 carries a very narrow sagittal area, rather than a crest, hut only in the little C. lemur 

 from the John Day does this area assume the lyrate form. This fact is of importance in 

 determining the primitive or secondary nature of the sagittal crest, concerning which 

 there has been some dispute. 



The frontals form relatively as much of the cranial roof as in Canis and have, when 

 viewed from above, an hour-glass shape, which is due to the deep postorbital constriction, 

 though the depth of this depression varies considerably in different individuals. The 

 postorbital processes are very small and owe their prominence entirely to the constric- 

 tion. The forehead is slightly convex, both transversely and longitudinally, though in 

 some sjiecimens it has a narrow and shallow depression along the median line, such as is 

 found, though much more distinctly, in modern species of both Canis and Vulpes. The 

 forehead is bounded by the obscurely marked supraciliary ridges converging posteriorly 

 to the sagittal crest, which is entirely upon the parietals, none of it being formed by the 

 frontals. Anteriorlv the frontals are eniar° - inated to receive the narrow nasals, and send 

 forward slender nasal processes, which are separated by short interspaces from the 

 ascending rami of the premaxillaries. A noteworthy difference from Daphcenus consists 

 in the absence of frontal sinuses, in which respect Cynodictis agrees with the alopecoid 

 series of the modern Canidce, as Daphcenus does with the thooid series. The significance 

 of this fact will be discussed in a subsequent chapter. 



The squamosal has a relatively small extension upon the side of the cranium, and 

 this portion of it has a different shape from that seen in the modern dogs, the pari- 

 etal suture descending very steeply forward from the occipital crest, while in the modern 

 genera this suture pursues a nearly horizontal course. From the base of the zygo- 

 matic process to the posttympanic process of the squamosal runs a projecting shelf, 

 which overhangs the auditory meatus and is much wider than in Canis or Vulpes, 

 though not so broad as in Cynodesmus, Hypotemnodon or I)<ijilm ,,u.<. The posttym- 

 panic process is not larger than in Canis, but is made more conspicuous by the absence 

 of any tubular meatus auditorius. The zygomatic process is relatively somewhat heavier 

 than in Vulpes, and in shape and proportions much like that of the wolves, though not 

 so strongly arched upward ; anteriorly it extends to the postorbital process of the 

 jugal. The glenoid cavity is broad ami the postglenoid process is proportionately heavier, 

 more extended transversely and it< distal end is more curved forward than in Canis. 

 There is no preglenoid ridge. 



The jugal also resembles that of Canis, though it displays some differences. Thus, 

 it is not quite so long as in the modern genus and does not extend so near to the glenoid 

 cavity: it has a less decided upward curvature, and the postorbital angle (it can hardly 

 be called a process) is even less conspicuous ; the masseteric surface is broader, more lat- 



