172 Prof. H. G. Seeley on the 



Ihe bone, which is only well preserved on the left side, is 

 essentially an anterior dismemberment of the postfrontal, and 

 it may possibly be prolonged downward to meet the malar 

 bone. 



The median upper border of the orbit is vascular and some- 

 what rugose. Tlie internal surface of the bones of the orbit 

 is smooth and regularly curved, and shows the sutures of the 

 frontal with the other bones. The orbit was probably deeper 

 than wide, the depth being 2| inches from the frontal bone 

 above to the part of the maxillary which is above the base of 

 the root of the tusk. The eye may have been slightly oblique 

 and possibly looked to a small extent outward and forward 

 as well as upward. The under surface of the postfrontal 

 bones is smoothly excavated. 



The external surface of the prefrontal bone differs in texture 

 from the frontal in being less smooth, and agrees in this 

 respect with the nasal bones^ from which it extends laterally 

 outward, and is defined by a distinct suture. 



The skull of Dicynodon tigriceps has shown that the nasal 

 bones extend transversely across the face, so as to meet the 

 frontal bones behind them, where their transverse width 

 exceeds the width of the prefrontal bones. In this genus 

 the nares are relatively further forward and differently con- 

 ditioned, so that the nasal bones are elongated from back to 

 front. They constitute the upper border of the nares, are 

 about 85 inches long and 2\ inches wide. In the median 

 line the nasal bones are overlapped in front by an unpaired 

 bone — the intermaxillary — and that overlap causes them to 

 appear to diverge as they extend forward. The hinder 

 border of the nasal bone meets the lachrymal, which is large 

 and placed between the ]irefrontal and nasal in front and the 

 maxillary behind. It extends forward into the nasal vacuity, 

 forming its hinder floor. The cavity which lodged the 

 lachrymal gland was behind the nostril and below the eye, 

 about 2^ inches long and /^ inch wide, rather narrower in 

 the middle. The lachrymal duct is circular and has the 

 usual position. 



The single unpaired condition of the intermaxillary is not 

 associated with a pair of preniaxillary bones in this animal. 

 'Ihe face comprises three regions — a narrow median anterior 

 area, 1^ to If inch wide, marked with a slightly elevated 

 median ridge, and j^arallel to this are the rounded angles 

 which separate this median anterior region from the oblique 

 lateral areas. Ihis long flat nose is very gently convex from 

 above downward. A well-defined suture extends from the 

 lower angle of the large diamond-shaped narine and divides the 



