54 MR, A. H. GARROD ON HALMATURUS LucTuosus. [Feb. 2, 
from most of the species of Macropus, although they are almost as 
well developed in the subgenus Lagorchestes as in D. luctuosa, and 
in that one only. 
The premolars of Dorcopsis are particularly interesting, presenting 
characteristic features which are more suggestive of its affinities than 
any other skeletal point. As to those in the upper jaw, their 
breadth from before backwards is very nearly or quite as great as 
that of the first and second molar together with the anterior of the 
two cusps of the third. The crown of the tooth on each side is 
prismatic in shape, with one of the angles forming the cutting-edge, 
the opposite side the base. A tubercle on the inner surface of the 
posterior end of the tooth disturbs the uniformity of the prismatic 
shape; it is continued forward along the margin of the lingual 
surface as a feebly developed ridge or cingulum. Opposite it, on 
the labial surface, a small tubercle is also to be found, larger in 
Dendrolagus, with a similar, slighter cingular expansion. 
From the thus somewhat swollen neck or cingulum several ridges 
with intervening depressions run at right angles, to end at the 
trenchant edge. These ridges differ considerably from those ob- 
served in the corresponding tooth of the genus Bettongia, in other 
points than their degree of obliquity: they are less numerous, and 
therefore further apart, because the tooth is considerably broader ; 
and they are continued as what look like tumefactions of their basal 
ends, into both the inner and outer cingulum. It may be here 
mentioned that the premclars of Hypsiprymunus proper (J. murinus, 
H. gilberti, and H. platyops) agree much more closely with Dor- 
copsis and Dendrolagus in the characters in which those genera differ 
from Bettongia. 
The mandibular premolars are much like those in the maxilla. 
They are not so broad, equalling only the two succeeding molars. 
They present a tumefaction or cingulum at the base of the crown ; 
but the posterior internal and external tubercles are not developed. 
In Macropus there is never any thing like the size of the premolars 
of Dorcopsis or Dendrolagus, although there is a considerable range 
of difference in different sections of the genus, which in J/acropus 
proper appears to me to be correlated with the length of ear rather 
than with any other character. In M. major their size and per- 
manency is but slight; and in most of the long-eared species they 
are not so broad as the first true molar. In M. dillardiert and 
MM. brunii they attain their maximum size proportionally ; and they 
are nearly as large in the subgenera Petrogale and Lagorchestes. 
In M. billardieri and M. brunii they are almost exact miniatures of 
those in Dorcopsis, except that the number of perpendicular ridges 
is fewer. 
Respecting the molars of Dorcopsis and Dendrolagus, they may 
be termed macropodiform, because, though much resembling those 
of the type genus, they present special characters. The two trans- 
verse prismatic ridges, with the small connecting bridge between 
them, are present, although the last-named structure is less _con- 
spicuous and narrower. The anterior minor ridge is also to be seen; 
