A NEW GENUS OF FOSSIL MABSVFIALS.— LONGMAN. 67 



sagittal suture to the t'ronto-nasal depression is praetieally a straight line, 

 which is parallel with the plane of the bony palate. There is no parietal 

 platform, and the cranial walls, when losing their curves of contact with the 

 occiput, slope in straight lines to their fractures. In the mid-parietal region 

 these walls form an angle of 50°. The lower moieties of the lateral walls are 

 missing. 



On the dorsal surface the sutures between the parietals and frontals are 

 obscured. In this area the sagittal crest bifurcates, as in Fliascolarctus; the 

 frontals rapidly widen and when in line with the inferior zygomatic processes, 

 they attain a breadth of 148 mm. This breadth is apparently continued 

 (contours incomplete) through the course of the fronto-nasal depression. The 

 concavity of this depression is wide, the sides and posterior wall sloping sharply 

 to the main frontal i)latform. The course of the fronto-nasal sutures cannot 

 be traced with accuracy. The terminal areas of the frontal liones are slightly 

 rugose on the slope of the depression, and there are a few very small nutrient 

 foramina. A small horn or frontal boss may have been attached here (r/. 

 Scott & Lord, 1920). 



Nasals. — From the frontal depression the nasals reach almost to a point 

 above the gnathion. Except for a slight convexity, which is double in the 

 anterior region where the median suture is open, they are surprisingly fiat on 

 their upper surface, which projects forward at an angle of about 18° to the plane 

 of the bony palate. Their course does not appear to be curved, or to terminate 

 in a deflected obtuse apex. The left-hand moiety, is perfect anteriorly, and is 

 S8 mm. in width. A right-hand fragment is sufficient to give fair evidence of 

 symmetry, and the approximate width would thus be 176 mm. There is no 

 evidence whatever of the presence of bony studs, of which Scott and Lord have 

 made interesting studies in Tasmanian material (A. mitchcUi), or of attachments, 

 for a horn, as first suggested by Macleay in his original description of 

 "Zygomaturus trilobus" in 1857 (quoted by Owen, 1859, p. 169). 



The lateral portions of the naso-maxillo-premaxillary region are, unfortu- 

 nately, too incomplete to be correctly allocated, and it has been thought 

 inadvisable to restore the missing parts. It is evident that the anterior portions 

 of the nasals projected clear of lateral supports for a distance of at least 75 mm. 

 Fragments of the sides, and especially one piece exhibiting the maxillary-nasal 

 suture, show the great strength of the bones supporting the main nasal arch. On 

 the inner median surface of the nasals, near the suture with the frontals, may be 

 seen two large sub-contiguous channels, 11 mm. wide and 5 mm. deep, and these 

 extend towards the anterior extremity where they are jnerged in the general 

 concavitv of the inner tables. 



