1 ( U4] The Ottawa Naturalist. 147 



to be a small separate bone, which is regarded as a supraorbital, 

 The slender postorbital bar is formed by a process sent down 

 from the postfrontal to meet one rising from the jugal. The 

 opening is bounded beneath by the jugal, and in front by the 

 prefontal, lachrymal and jugal. In the upper anterior part of 

 the opening there is a conspicuous emargination of the rim 

 bounded in front and above by the prefontal and below by the 

 lachrymal which sends up a short, stout process from its 

 posterior border behind the emargination. What appears to 

 be the opening of the lachrymal canal is here visible within the 

 indentation. 



The lateral temporal fossa is more than twice as high as 

 wide and is narrowly rounded at its front lower termination. 

 It is bounded in its lower half by the jugal, and in its upper half 

 by the postfrontal anteriorly, by the postfrontal and squamosal 

 above and by the squamosal and quadrate posteriorly. The 

 jugal connects with the quadrate for some distance above the 

 upper end of the quadrato- jugal. 



Anteriorly, the jugal effects a strong union with the maxilla 

 below and the lachrymal above. The lachrymal meets the 

 maxilla below in advance of its union with the jugal and connects 

 with the nasal for a short distance, separating the prefontal from 

 the long, backwardly directed lower limb of the premaxilla. 



The nasal extends back as far as the posterior end of the 

 postfrontal and meets the frontal in a coarsely dentate, trans- 

 verse suture. The frontal is about as broad as long and does 

 not reach the orbital rim. Antero-laterally this bone connects 

 with the postfrontal and supraorbital, postero-laterally it is met 

 the postfrontal and behind by the parietal. The naso-frontal 

 surface between the eyes is flat and at a slightly lowel lever than 

 the upper orbital rims. 



The supratemporal fossa is angularly oval, with the greater 

 diameter fore and aft. It is enclosed in front a ] - jualh by 



the parietal and postfrontal, and on the outside by the post- 

 frontal and squamosal. The frontal does not quite reach the 

 anterior margin of the fossa. The squamosal passes inward 

 behind the opening to meet the parietal, but to what extent the 

 latter bone contributes to the formation of the posterior border 

 is not known, as the position of the squamosO-parietal suture. 

 has not vet been determined. The coalesced parietak form a 

 narrow median bar, separating the two openings. 



Viewing the skull from the side, the thin edge of the angular 

 is visil le for a short distance beneath the posterior end of the 

 dentarv, and the articular appears to a limited extent at the 

 extreme end of the mandible above the surangular. This last 



