A NEW GENUS OF FOSSIL MABSUPIALS.— LONGMAN. 6» 



Inferior Lateral Processes. — Across the processes the extreme breadth 

 is 680 mm. On the left-hand side the maximum transverse diameter of the 

 inferior lateral process is 231 mm. The vertical height of the process in its. 

 lateral extension beyond the arch is 121 mm. The maximum thickness is 47 mm. 

 The extreme height of the combined elements, from the superior border of the 

 squamosal to the inferior border of the vast processes (taken from parallels) 

 is no less than 285 mm. When the cranium is resting on the inferior borders^ 

 of the processes the molar series are 64 mm. above the surface. This downward 

 development is surpassed by the inferior processes of Mylodou, but in that 

 mammal there are no lateral extensions. 



The processes flare outward almost at right angles to the sagittal plane, 

 as may be seen from Plate V. They are not, however, straight, but slightly 

 curved, the lateral margins being in advance. There are prominent rugose areas- 

 on the superior border of these processes, just at the origin of their lateral 

 extensions, these being doul)tless for the attachment of parts of the masseteric 

 muscles. 



The origin of the zygomatic process of the maxilla is primarily a vertical 

 plate which abuts on practically the whole of the vertical face of the maxilla, 

 commencing parallel with the anterior lobe of the third molar, and being about 

 30 mm. in thickness ; this is supported above by the horizontal orbital plate 

 14 mm. thick, wliicJb is produced antcriorhj at right angles to the vertical 

 fonstitucnt, forming a triangular platform which is continuous behind with the 

 superior border of the maxilla : this horizontal orbital platform unites the 

 vertical plate with the strong convex bar which forms the lower border of the 

 orbit, and through the inner root of which the large infra-orbital foramen passes. 

 The lateral extension of this bar forms a strong supporting buttress for the 

 accessory processes. With the exception of the suborbital bar, the whole pier 

 is composed of maxillary elements, but the sutures at the orbit cannot positively 

 be traced, owing to fractures. The w^hole architecture of this part of the skull 

 is quite unlike the piers of the zygomata in Macleay 's cast, and is also absolutely 

 distinct from other cranial fragments in the Queensland ]\Iuseum attributed to 

 X. I'ictoriee. The deep rectangular suborbital recess is a marked feature. 



Of the extreme Avidth of the accessory process, the maxilla forms less than 

 one third. The zygomatico-maxillary sutures on the anterior surface are 

 produced laterally to a far greater extent than are those on the posterior surface, 

 giving the maxillary element, as illustrated in Plate V, a greater proportion 

 than really exists. It may here be noted, as W. K. Gregory (1910, p. 221) has. 

 pointed out, that many of the cranial bones of marsupials are very oblique in 

 their areas of contact. 



Maxilla and Molars. — The bony palate is well preserved and there are na 

 signs of fenestrations. The tioor is slightly concave transversely, with a median 



