22 The Ottawa Naturalist. [May 



The skull derives its great breadth principally from the 

 outward spread of the zygomatic arches, a measurement across 

 them nearly equalling three-fourths the length of the skull. In 

 advance of the orbits it is short and broad. The forehead is high, 

 moderately broad, and descends convexly downward in front. 

 The breadth across the postorbital processes of the frontals is 

 contained about two and a half times in the skull's length. 

 Viewing the skull from above there is a rapid narrowing behind 

 the postorbital process which is accentuated by the general 

 and marked depression of the surface between the upper 

 portion of the base of the zygomatic arch and the sagittal 

 crest, a very slight swelling in the middle of this surface alone 

 saving it from being concave throughout. Between the inner 

 limits of the temporal fossae the breadth of the brain case 

 is slightly less than one-third the maximum breadth of the skull. 

 The sagittal crest is high and strongly developed. In outline, as 

 seen from above, the cranium is pointed behind, the lambdoidal 

 ridges, marking the upper limit of the occipital bone, meeting 

 at an angle of 90. The inion overhangs the posterior curve of 

 the occipital condyles to the extent of about 43 mm. The surface 

 of the occipital is strongly concave from the condyles up and is 

 rather flat in a transverse direction. A high, thin occipital crest 

 is continuous between the external occipital protuberance 

 (inion) and the upper margin of the foramen magnum, and, as 

 already mentioned, there is a considerable overhang to the upper 

 portion of the occiput. 



The palate is broad and, for the most part, slightly concave, 

 both longitudinally and transversely, but in advance of the 

 anterior palatine foramina its surface curves rapidly downward. 

 From the second molars it narrows evenly and rapidly backward 

 to the posterior nares, which are set rather far back. In line with 

 the posterior nares a horizontal measurement taken across the 

 vertical plates of the palatines is only 70 mm. The posterior 

 narial emargination is rather narrowly rounded anteriorly. The 

 distance from the posterior nares to the occipital condyles is 

 short compared wiht the length of the hard palate. The zygo- 

 matic fossae are triangular and as wide as long, their greatest 

 width being but slightly in advance of the glenoid cavity. The 

 anterior basal margin of the occipital condyles, viewing these 

 surfaces from beneath, form an even transverse curve arching 

 but slightly forward, the flatness of the curve being con- 

 spicuous. 



Between the canine and the fourth premolar are three 

 alveoli, which are interpreted as being those for the first premolar 

 and for a double-rooted third premolar. The anterior one of 

 these three alveoli is close to the canine. Those for the supposed 



