RECORDS OF W.A. MUSEUM. 
[6j 
with rectilinear crests, feeble lines and sharp angles, upper molars 
without distinct anterior links, lower seldom without posterior 
talons. . . . These posterior basal talons are generally present as 
erect plates, raised rims, or a mere but decided bulging of the base.” 
This description applies to the specimens under consideration, 
and is made to embrace a number of Owen’s species, as De Vis 
found, after examining 330 specimens, that there was a good deal 
of variation, and that intervening forms made the gradations so 
minute that it was quite impossible to draw any hard and fast line 
of separation. He states 1 : “ The degree of variation in the length 
of the cheek teeth found in this species is less than that shown by 
Halmaturus ruficollis, and the premolar has a more restricted range 
of length than in most of the larger existing Wallabies. On the 
other hand, the width of the teeth and the depth of the mandible 
have a somewhat greater range of measurement than in living 
species, and in thickness the ramus is decidedly more variable ; but, 
as in all the dimensions, the extremes are reached by insensible 
gradations, excess even in the width of the teeth must be considered 
a peculiarity of the species. ... It is quite the most abundant 
macropod of its period.” 
The specimens from Balladonia resemble the mandible figured 
by Owen in Phil. Trans., 1874 (plate xxv., figures 7 and 8), as 
M. auak, and as regards the teeth they most nearly approach those 
of P. mimas of plate xxvi., figures 1, 2 and 3, which they slightly 
exceed in width. 
The teeth of P. mimas (plate xxiv., figs. 13 and 14, and plate 
xxvi., figs. 4, 5 and 6), the P. roechus (plate xxvii., figs. 10, 11 and 
12), and the P. antaeus, figured on plate cx. of “ Extinct Mammals 
of Australia,” all show points of resemblance to the teeth from 
Balladonia, but differ in the relatively less width of the crowns. 
Remains of this species have been obtained in all the Eastern 
States and South Australia, but are now recorded for the first time 
from deposits in Western Australia. 
It was probably one of the largest Kangaroos, rivalling the 
huge M. titan, but giving pride of place to its contemporaries, the 
genera Procoptodon and Palorchestes which have likewise become 
extinct. 
1 Loc. cit. , p. 106. 
