198 THE SKULL. [CHAP. 



zygoma. The face is greatly elongated, tapering forwards, 

 and compressed laterally. The nasals are long and narrow, 

 and the apertures of the nares small and nearly terminal. 

 The premaxillae send up long processes on each side of 

 the nasals, which, however, do not meet the frontals. The 

 lacrymal has a considerable facial portion ; and, as in 

 other Ungulata, the malar encroaches considerably on the 

 face, uniting with the lacrymal. 



At the anterior extremity of the mesethmoid a peculiar 

 ossicle (prenasat) is developed, which strengthens the cartil- 

 aginous snout. 



The palate is long and narrow, and extends posteriorly 

 beyond the last molar tooth. The pterygoid fossae are well 

 marked, being chiefly formed by the well-developed ptery- 

 goid plates of the alisphenoid ; the true pterygoids are very 

 slender. There are very long, slender, compressed par- 

 occipital processes, curved forwards. 



The squamosal and tympanic are ankylosed together ; the 

 floor of the long, narrow, upward-directed auditory meatus 

 is formed by the tympanic, wedged in a cleft of the squa- 

 mosal, between the hinder edge of the glenoid fossa (there 

 being no postglenoid process) and a long descending post~ 

 tympanic process which articulates with the exoccipital. 



Inferiorly the tympanic is dilated into a very prominent 

 bulla, peculiarly elongated vertically, and rather compressed 

 from side to side. The interior of this bulla is filled with 

 cancellous bony tissue. 



The periotic is small and not ankylosed to the tympanic 

 or squamosal. The mastoid portion is quite rudimentary, 

 being merely a short scale-like prolongation upwards and 

 backwards, lying on the inner surface of the squamosal, and 

 making no appearance on the external surface of the skull. 

 The tympanohyals are very inconspicuous, being small, and 



