1 9 1 7 I The Ottawa Naturalist. 69 



postfrontal by means of a long, ascending process which passes on the 

 inner side of the inner wall of the postfrontal pocket. 



Quadrato-jugal. A thin, subtriangular plate, extensively over- 

 lapped by the jugal. Posteriorly it connects with the quadrate which 

 is emarginated to receive it. 



Quadrate. A transversely compressed, nearly upright bar from 

 whose inner surface a large, thin flange is directed inward and for- 

 ward It is in contact antero-externally, below its midlength, with 

 the quadrato-jugal, with the pterygoid internally by means of the 

 flange, with the squamosal superiorly, and with the surangular and 

 articular (mandibular cotylus) at its lower end. A spur from the 

 squamosal descends on and is suturally united with the anterior border 

 of the quadrate below its head. 



Ectopterygoid. Connects the maxillary and pterygoid, lying for 

 the most part external to both. Is longer than high, and is thin and 

 overlapping except in a small inwardly thickened area which fits 

 inward into the postero-maxillary notch suturally uniting the maxillary 

 and pterygoid. It is broadest behind, where it flares thinly over the 

 pterygoid, and extends narrowly forward in the postero-external, 

 concave area of the maxillary. The upper and lower borders of the 

 bone, where it begins to broaden posteriorly, fit into two grooves in the 

 maxillary, one in the lower surface of the postero-maxillary process, 

 the other curving downward round the posterior end of the maxillary 

 ridge. 



Maxillary. Connects suturally with the premaxillary, nasal. 

 lachrymal, jugal, palatine, pterygoid and ectopterygoid bones. Is roughly 

 triangular in lateral outline, highest at midlength, and thickest at 

 about midlength below the large, rugose, external surface of attach- 

 ment for the jugal. The inner face is rather flat in comparison with 

 the varied relief of the outer one. The superior border slopes down 

 from the apex to either end terminating in thin processes of which the 

 anterior one is the larger. The anterior portion of the border is 

 shallowly grooved, for a considerable distance in advance of the apical 

 elevation, for the reception of the spur directed forward from the 

 lower border of the nasal. The postero-superior border is in sutural 

 contact with the lower edge of the palatine. The robust, rounded 

 posterior end is clasped by the lowermost part of the pterygoid whose 

 anterior border, in its upward course to reach the palatine, passes on 

 the inner side of the postero-maxillary process. The ectopterygoid fills 

 the emargination below this process, and extends narrowly and thinly 

 forward for some distance in a depressed area of the external face 

 below the postero-superior border. A less pronounced depression of 

 the external face below the antero-superior border receives the ascend- 

 ing lower premaxillary limb. The teeth are in fifty-one to fifty-three 



