7() MEMOIRS OF THE QUEENSLAND MUSEUM. 



Taking only dontal characteis into consideration, these results can be- 

 tabulated thus : — 



Incisors s — 



Upper premolars oval, tubcrculatcd . . . . . . Notothcrium, sensu stricto^ 



Upper premolars subtriangular. 



Cusp, single, transverse, with a shallow posterior cleft . . . . Euryzyyoma. 



Labial cusp extended antero-posteriorly .. .. " Nototherium victorice 



and inermc. "' 

 Incisors j — 



Ujjper premolar subtriangular .. .. .. .. .. .. Euowenia.. 



These dental characters are, of course, supplemented by other important 

 features, as detailed elsewhere. 



Xototlierium inerme and victorice Avere included by Lydekker (1887,, 

 p. 162) as synonyms of N. ^nitchelli, but the same author later (1889, p. 152) 

 suggested that ^' Nototkerium dunense" of De Vis was to be associated Avith 

 .Y. inerme, and probably a distinct species. But N. inerme with its inconspicuous 

 lower incisors cannot be associated with N. dunense, for the type mandible of 

 the later species, although scarcely mature, is well armed wath a large incisor. 

 To resolve one as a sex variation of the other does not seem justifiable. Owen's 

 maxillary heautotype of N. inerme as illustrated in Plate XLIII, and as described 

 on p. 277 of the ''Extinct Mammals of Australia," has a "triangular tract of 

 dentine exposed extended antero-posteriorly," and is certainly not conspecific 

 with the premolars in our cranium. 



It may here be mentioned that G. Krefft used, in manuscript only, the 

 name "Zygomaturus macleayi" for a perfect palate figured in Plate VII of 

 his "Australian Fossil Kemains, " published in 1882 as a Parliamentary paper. 

 We are indebted to Mr. C. Hedley for a copy of the unpublished explanation 

 of the plates. The structure of the premolars cannot be satisfactorily defined 

 from the illustration, but these teeth were evidently of the subtriangular type. 



Scott and Lord (1920) have divided Xototherian crania into megaeerathine 

 and leptocerathine groups, but our specimens cannot be placed in their diagnostic 

 tables. The wide nasals of Euryznyoma are associated Avith a parietal crest,. 

 AA'ith, of course, other discrepancies. The useful AA'ork done by the Tasmanian 

 authors only applies to the material under their review. 



Euowenia grata and rohusta De Vis (1887 and 1891) are placed by 

 Scott and Lord with Nototherium tasmanicum. They do not, however, give 

 sufficient evidence for the association of the cranium and mandibles described 

 by De Vis, with two upper incisors only on each side and a small subtriangular 

 premolar, Avith N. tasmanicum Avith three pairs of incisors and a large oval 

 premolar. 



