34 



Firmly articulated by extensive reciprocally indented sutures, at one end with the 

 maxillary (si), at the other end with the zygomatic bones (a?), and giving an extensive 

 surface of attachment, by a peculiar upward prolongation, to fasciculi of the temporal 

 muscle, it afforded the requisite fixity for the origins of the large and complex mas- 

 seter. 



The suture with the maxillary is in great part obliterated in the skull under descrip- 

 tion ; but a portion remaining on both sides shows that the malar ascended to the 

 level of the antorbital foramen, Plate XIV. fig. 2, r : it forms the lower and a great 

 part of the hinder boundary of the orbit ; the latter by a triangular, slightly bent 

 postorbital process (Plate XII. fig. 1 , a), which almost touches the corresponding 

 more slender process of the frontal (ib. u). The ascending process (ib. c) is a long, 

 narrow, unequal-sided triangle with an obtuse apex ; the descending process (d) is a 

 longer and stronger one, extending, when the mouth is shut, outside and for three 

 inches below the alveolar border of the lower jaw : its extremity is obtuse and re- 

 curved. The fourth process (ib. b), which may be called the 'zygomatic' one, ex- 

 tends beneath the end of the corresponding process of the temporal bone, but the 

 obliteration of the suture in the present skull prevents a precise definition of its 

 limits. The whole outer surface of the malar is slightly convex, moderately smooth, 

 with a defined surface for muscular attachment near the back part of the base of 

 the descending process. The inner surface shows, by its well-marked ridges and 

 depressions, the vigorous action of the muscular fasciculi which derived their origin 

 from that part. 



The orbit (Plate XII. fig. 1, o), of proportionally small size, as in all large mam- 

 malian quadrupeds, presents a long vertically oval form ; or rather, by the convex 

 border of the malar (a), is reniforra. Its peripheral contour is almost completed by 

 the descending postorbital process of the frontal (ib. u) in the present skull ; anterior 

 to which the prominent boundary is effaced by a broad smooth channel, where the 

 orbital surface is more directly continued upon the facial surface of the maxillary: 

 this part answers to the supraciliary notch in quadrupeds. The lacrymal bone being 

 completely coalescent, if not connate, with the maxillary, is recognisable only by the 

 lacrymal foramen (ib. /), which is just within or behind the obtuse anterior border of 

 the orbit. Admitting the essential presence of the lacrymal by this character, it then 

 combines with the frontal, maxillary and malar bones, to form the contour of the 

 orbit. Within this frame, the orbit, as already remarked, communicates extensively 

 with the temporal fossa. 



The anterior aperture of the bony nasal canal (Plate XIV. fig. 2, m, n, w) is sub- 

 circular, and is formed by the nasals, maxillaries and premaxillaries ; the deep ver- 

 tical sides being contributed wholly by the maxillaries. 



The formation of the external bony aperture of the organ of hearing has already 

 been described. 



Mandible. — The chief characteristic of the mandible or lower jaw is the near 



