HIS 



near the outer angle of the fore lobe, and describing a slight bend in its forward course 

 to expand upon the hind part of the " prebasal ridge" nearer its outer than its inner 

 end. The projecting angle of the " link" is directed inward. The valley between the 

 anterior lobe and the prebasal ridge is thus divided into two hollows, the inner one 

 being the largest. The inner border of the prebasal ridge is sharp, and abuts against 

 nearly the middle of the back part of the antecedent tooth (d 4). The outer border of 

 the prebasal ridge is thicker than the inner one, less inclined inward, and projects 

 freely a little external to the level of the hind lobe of d 4. The back part of this lobe 

 is entire ; it shows a submedian posterior vertical indent ; there is no perceptible trace 

 of basal ridge. 



The mid link (fig. 17, Plate LXXXII.) repeats the characters of the fore link, save 

 that it sinks lower to connect itself with the anterior lobe, leaving more of the summit of 

 that lobe free than is left to the prebasal ridge. The summit of the anterior ridge of 

 m 1 inclines a little forward as it crosses the too^h from without inward, and is slightly 

 bent with the convexity backward. The mark of wear, which in the young animal 

 owning this tooth had not exposed the dentine, affects the hinder slope of the summit 

 of the transverse ridge. 



The characters of the crown in the two lower grinding-teeth of the type specimen of 

 Macropus Titan above described are, in the main, those of the largest existing repre- 

 sentatives of the true or subgenerically restricted Macropus. 



In the lower jaw of Macropus major (Plate LXXX. fig. 15) the prebasal ridge (fig. 16,/) 

 of m 1 and m 2 has a like size and shape, and is connected with the anterior lobe by a 

 similar link ; but this is less bent inwardly in its forward course. In Macropus rufus 

 the prebasal ridge is less developed (Plate LXXXI. fig. 4) ; there is no postbasal ridge or 

 talon. A feeble vertical notch is shown by the back part of m 1 and m 2 ; this does not 

 appear in m 3. The proportion of length to breadth of the grinding-surface of the true 

 molars is the same in the recent as in the extinct species compared ; the difference is 

 mainly in size. 



In a portion of the right mandibular ramus of Macropus Titan, with the three posterior 

 molars in situ, these, like the single entire molar in Plate LXXXII. fig. 17, m i, show 

 a proportionally greater antero-posterior extent of the prebasal ridge than in Macropus 

 major or Macropus (Osphranter) rufus. Of the latter existing species* Mr. Gould, 

 F.R.S., was so good as to place in my hands, for the purpose of these comparisons, the 

 jaws and teeth of a male which he killed between the rivers Murray and Adelaide, 

 Australia ; it measured 8 feet 2 inches from the nose to the end of the tail, and was 

 the largest Kangaroo which that eminent naturalist saw in the continent of which he 

 has so admirably illustrated the rich ornithology as well as its singular mammalogy. 



These specimens I presented, in Mr. Gould's name, to the Royal College of Surgeonsf , 

 after their application to the requisite comparisons with the fossils from the Wellington 



* Theu known as the Macropus laniger. 



t See ' Catalogue of the Fossil Mammals and Birds ' &c., 4to, 1845, pp. 324, 325, Nos. 1510, 1511. 



