352 PROF. OWEN ON A NEW SPECIES OF STHENURUS. [Apr. 17, 
5. On a new Species of Sthenurus, with Remarks on the 
Relation of the Genus to Dorcopsis, Miiller!. By 
Professor Owen, C.B., F.R.S., F.Z.S., &c. 
[Received April 4, 1877.] 
(Plates XXXVII. & XXXVIII.) 
The present species of extinct Kangaroo is founded on a fossil 
fragment of skull including the molar series of both sides of the 
upper jaw with the intervening bony palate (see Plate XX XVII.). 
The reference to the genus Sthenurus in Prof. Garrod’s excellent 
memoir on Dorcopsis luctuosus* eucourages me to think the follow- 
ing notes may not be unacceptable to the Society, which has occa- 
sionally admitted illustrations of extinct animals into its publications. 
The fossil was found in a ‘‘ rocky alluvial deposit’ in the shaft of 
a gold-lead ‘in the county of Phillip, New South Wales, Australia, 
and was transmitted to me-by the Rev. William Branthwaite Clarke, 
M.A., F.R.S., the veteran geologist of New South Wales. The 
fossil is in a massive petrified condition. 
The genus Sthenurus is chiefly characterized by the configuration 
and fore-and-aft extent of the premolar (Plate XXXVIII. figs. 1, 5, 
12, ps),which exceeds that of the following molar (ib. figs. 5, 12, d 4) 
commonly to the extent of one half of the next molar, m1. The 
premolar in the upper jaw has an outer (ib. figs. 3, 7, 14 d) and an 
inner (ib. ib. e) trenchant plate, the latter being lower in extent, 
almost basal in position; the plates are united together by two or 
more low transverse ridges. The crown of the tooth is thus partly 
trenchant, partly triturant. 
The molars have the two transverse lobes (ib. figs. 4, 7, 8,14, 15, 
a and &) of the macropodal type, well developed, with their summits 
trenchant and slightly curved prior to abrasion, with a “ prebasal 
ridge”’ (ib. figs. 4, 8, 15, #) and a low and small “mid link”? (ib, 
fig. 8, 7), continued at almost a right angle forwards from the inner 
inflection of the fore lobe. The hind lobe of the last molar (m 3) is 
a little narrower than the fore lobe. 
The upper incisors (ib. fig. 11) work on the same horizontal plane ; 
and the crown of the third (¢ 3) exceeds that of the first (71) in 
fore-and-aft extent. 
The smallest species of the extinct genus known at the date of my 
eighth paper on the ‘ Fossil Mammals of Australia” * was the type 
one (Sthenurus atlas) in which the fore-and-aft extent of the crown of 
the upper premolar (ib. figs. 5, 6, 7, p 3) is 9 lines, that of the entire 
permanent series of upper molars being 2 inches 11 lines. A second 
species of Sthenurus (S. brehus) has the upper premolar (ib. figs. 
12, 13, 14, p 3) 10 lines in fore-and-aft extent ; that of the perma- 
" Zoogd. vy. den Indischen Archipel, pt. 4, pl. xxiii. (skull and dentition, figs. 7 
and 8), plate xxiv. fig. 7 (Hypsiprymnus brunii; Dorcopsis in text) 1841. 
? Proc. Zool. Soc. 1875, pp. 48 and 58. 
° Phil. Trans. 1874, p. 245, pls. xxii. and xxiy. 
