BY C. W. DE VIS. 
119 
destroy any diagnostic features which may have existed in earlier 
life. It is worse than idle to confer on such a fossil names which 
cannot with certainty be extended to others. 
Halmaturus sp. 
A portion of a right mandibular ramus of an aged individual 
with the last three and major part of the first true molars. The 
estimated length of the molar series is 34'5; the last three teeth 
measure 27'1. The width of the series at m. 3 is 7*1. The mid 
depth of the mandible is 18*5; its thickness 10 "9. 
The width of the teeth falls within the range of that in //. 
ayilis, ualabatus and ruficollis. The depth of the mandible would 
allow it to be referred either to agilis or ruficollis; its thickness 
to either of the large wallabies or to M. parry i. But the species 
is readily distinguished from II. ualabatus, to which, among 
modern kinds, it has the greatest resemblance by the greater 
length and width of the anterior talon, which forms a much 
larger portion of the whole than in the recent tooth. In conse- 
quence of this amplification of the talon the tooth is elongated; 
selecting a mandible of II. ualabatus of the same age as the fossil, 
and with teeth of the same width, we find that the length of the 
series of true molars in the fossil is a tenth greater than in the 
living species, the talons being on the average a millimetre longer. 
Until the premolar is known the species may be left unnamed. 
Halmaturus sp. 
Molars with rather straight crests, subrotund angles, and 
moderately strong links; without posterior groove or talon; 
smooth. 
Dimensions. 
Mandibular. — The last three cheek-teeth measure 25'1 in 
length. The width of in.' 3 is 5-9. Posterior depth 14-8; thick- 
ness 11*0. 
So far as it goes the fossil corresponds in size with II. dorsalis, 
and it is without any distinct marks of differentiation from that 
species; but as it is equally without characters, apart from 
