412 



collection in Wellington Valley, described and figured in his work published in 1838*. 

 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 LXXX11I. figs. 10 & 11), including 

 the antepenultimate and penultimate molars, and the sockets and fangs of the premolar 

 I p t) and of the first (V/ *) and last (m s) two-ridged molars. The two molars (m i 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 

 Tit mi, 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. 13, Plate 

 LXXX1IL). The depth of the jaw containing the teeth was greater than in Macropus 

 rufvs (of which a corresponding part of the mandible of a large individual is given in 

 fig. 14, ib.). 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. 



§ 4. Osphranter Cooperi, Ow. — The subject of figs. 17 &18, Plate LXXX1V., is the 

 fore part of the left mandibular ramus of an aged individual of a Wallaroo, of the size of 

 Osphranter robustm. It retains the first three molars (p 3, d 4, m 1), the second of which, 

 as having been longest in place, has the crown worn down to its base, from within 

 obliquely outwards, and in a rather greater degree than in the corresponding tooth of the 

 recent species compared, the mandible of which is the subject of fig. 13, Plate LXXX. 

 The premolar Q> 3) shows three small tubercles on its working-surface, arranged from before 

 backward ; the crown is subcompressed, and very slightly thickened behind ; the inner 

 surface of the fore part of the crown is gibbous, as in Osphranter, and its proportions 

 are as in Osphranter robustm. The degree of wear of the next tooth is such as would 

 be incompatible with the retention of the foremost if it were the deciduous tooth, d 2 ; 

 but, for decisive evidence, I removed the inner wall of the ramus where the germ of p j 

 would have been, and there was no trace of such successional tooth. The present 

 fossil, therefore, has come from a fully mature individual. A species of true Macropus 

 would not have retained the premolar or the following tooth at this age, or have kept 

 d » with a crown so far worn down. Thus the fossil accords with Osphranter in the 

 * Three Expeditions &c., 8vo, vol. ii. t Op. cit. 4to, 1845, p. 328. 



