260 
PROFESSOR OWEN ON THE FOSSIL MAMMALS OF AUSTRALIA. 
of this species. But though the depth of the mandible at the interval between d 4 and 
m 1 is nearly half an inch greater than in the subject of fig. 11, or in the Oxford speci- 
men (Plate XXII. figs. 1 3, 15), the teeth are not much larger. A figure of the working- 
surface of the last molar in this large Macropus Titan is given in fig. 14, and one 
of the hind surface of the same tooth in fig. 15, to exemplify the characteristic pit there 
in the fossil. 
In the hind part of a mandibular ramus of a fine old Macropus Titan, with the last 
molar well worn, and now much in advance of the coronoid process, the depth of the 
jaw behind this tooth is 1 inch 6 lines, and the same at the interval between m 2 and 
the debris of the socket of m 1 *. 
§ 3. Macropus affinis , Ow. — In a small collection of Marsupial fossils made by Sir 
Thomas Mitchell, C.B., in a survey undertaken after his return to Australia in 1839, 
and which he was so good as to transmit to the Boyal College of Surgeons, there were 
confirmatory evidences of the two large species represented by the fossils of his first 
collection in Wellington Valley, described and figured in his work published in 1838f, 
and also indications of a third species of large Kangaroo, which I described in my 
Catalogue of the Fossil Mammalia of the Museum of the College, and referred to a 
Macropus affinis\. This second collection was obtained, according to the notes accom- 
panying it, “ from the alluvial or newer tertiary deposits in the bed of the Condamine 
river, west of Moreton Bay.” 
The best evidence it contained of the Macropus affinis was a portion of the left man- 
dibular ramus, now for the first time figured (Plate XXIII. figs. 10 & 11), -including the 
antepenultimate and penultimate molars, and the sockets and fangs of the premolar (p 3) 
and of the first ( d 4) and last (m 3) two-ridged molars. The two molars (m 1 and m 2) 
retaining their crowns showed the specimen to have come from an aged individual. 
The pattern of that of m 1 had been worn away, with mere indications of the two chief 
divisions and the prebasal. ridge. The crown of the penultimate molar agreed in its 
general proportions more with that of Macropus Atlas than with that of Macropus 
Titan, but was narrower in proportion to its antero-posterior diameter than in Macropus 
Atlas, and the mid link was more developed. From its homologue in Macropus Titan 
the tooth differed in having no trace of a postbasal ridge (compare with fig. 1 3, Plate 
XXIII.). The depth of the jaw containing the teeth was greater than in Macropus 
rufus (of which a corresponding part of the mandible of a large individual is giv^n in 
fig. 14, Plate XXIII.). The teeth, however, indicate a species of less size than either of 
the two extinct ones above cited. I therefore continue to regard this fossil as evidence 
of an extinct Kangaroo of intermediate proportions between the largest known living 
species and those defined in my original memoir, and of which additional illustrations 
are given in the present. 
* This is the specimen alluded to as having been received, since the present paper was prepared, in the last 
collection of fossils from the freshwater deposits of Queensland, transmitted by George Bennett, M.D., F.L.S. 
t Three Expeditions &c., 8vo, vol. ii. + Op. cit. 4to, 1845, p. 328. 
