104 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. XIV. 



smaller than in Perameles and Sarcophilus, smaller also than in some 

 diprotodonts, but relatively quite as large as in others. Its proportions 

 are nearly as in the didelphids and smaller dasyurids. The glenoid 

 fossa is considerably above the basicranial axis and is distinctly longer 

 than wide. Except on its extreme outer edge where the end of the 

 jugal bounds it, it is open in front. Posteriorly it is bounded on the 

 outer side by a papillate bony elevation which is unconnected with the 

 tympanic and has only very slight transverse extent. The general 

 features of the glenoid fossa are thus somewhat intermediate between 

 those in polyprotodonts and in diprotodonts. The transverse extent 

 and the broad platelike posterior boundary usually found in polyproto- 

 donts are changed in the direction of the narrower more open condition 

 of the diprotodonts which allows of greater antero-posterior motion of 

 the jaws in conformity with the requirements of their dentition. The 

 arrangement of the foramina at the base of the squamosal is slightly 

 different from that of the Didelphiidae and similar to that in the smaller 

 Dasyuridae and the Peramelidae. As in these, the postzygomatic fora- 

 men is lacking and the postglenoid and subsquamosal are closely asso- 

 ciated. The subsquamosal foramen opens laterally just behind the 

 postglenoid process and the postglenoid foramen antero-ventrally 

 between the postglenoid process and the superior end of the tympanic. 

 A thin bony plate bounds the subsquamosal foramen ventrally and 

 extends from the postglenoid process to a short flat mastoid process of 

 the squamosal. 



Occipitals. Contrary to the usual condition in marsupials, supra- 

 occipital, exoccipitals and basioccipital are completely ankylosed in 

 adult skulls making it impossible to determine their exact boundaries. 

 In other forms, especially among polyprotodonts, the sutures separating 

 these bones are usually obvious. The supraoccipital shows no clear 

 indication of a forward extension to the dorsal surface of the skull and 

 the median occipital region is smooth without any sharp angle between 

 the dorsal and occipital surfaces. Laterally a slight ridge rises on each 

 side suggesting a lambdoid crest at the union of the supraoccipital and 

 the parietals. 



The exoccipitals are small and extend but little beyond the condyles. 

 Probably they do not meet above the foramen magnum. Small paroc- 

 cipital processes lie prostrate between the mastoid and the periotic and 

 do not form projecting points. Their condition is nearly the same as in 

 Perameles and Myrmecobius but different from other forms examined. 

 The exoccipitals are perforated by two small condylar foramina near the 

 apparent line of union with the basioccipital. 



The basioccipital is deeply cleft by the inferior lip of the foramen 



