^riiuling-surface is different and much more complex, of itself indicating a distinct genus 

 if not subfamily of Maeropodidir. 



The prebasal ridge (f) is narrower than in Sthenurus ; it descends (the tooth being 

 viewed prone) from the fore part of the outer angle of the front lobe (a) and then passes 

 inward with a slighter descent to the fore part of the base of the inner half of the front 

 lobe, subsiding before attaining the inner side of that lobe. The fore link (s) is feebly 

 represented by a vertical ridge on the fore part of the front lobe, nearer its outer than 

 inner end, the rest of that fore surface being marked by more minute vertical ridges 

 and grooves. The hind surface of the front lobe is bounded by sharp subvertical ridges, 

 respectively descending, with a slight degree of convergence, from the hind part of the 

 outer and inner angles of the front lobe. In the transverse concavity of the hind 

 surface of that lobe, so bounded, two stronger sharp vertical ridges of enamel descend 

 toward the intervening valley, the outer ridge being continued backward across the 

 valley as the 1 mid link' (r), with a slightly sinuous course, convexly outward. The hind 

 surface of the hind lobe (ib. fig. 5, m 2) almost repeats the characters of that of the front 

 lobe; the inner (rj) of the two submedian vertical ridges in the concavity of such surface 

 expands at its base into the convexity of that part of the molar ; the outer submedian 

 ridge is minute. From the outer lateral or boundary-ridge a sharp vertical plate of 

 enamel (h) is directed inward, and there are some minor sculpturings of this part of the 

 hind surface. Its basal part is somewhat bulging and smooth, as are the outer and 

 inner swollen ends of the two main transverse ridges or lobes (ib. fig. 6, a, b). 



The second molar (m 2) is rather larger than the first ; both are feebly abraded along 

 the fore part of the transverse summits of the wedge-shaped lobes, but not so far as to 

 expose the dentine ; both teeth are behind the back surface of the masseteric process 

 (ai»). These signs of immaturity were associated with and confirmed by the presence of the 

 undeveloped and unextricated premolar (Plate XC. figs. 2, 3, 4, p 3) ; it was so far advanced 

 as to have pushed its crown to near the level of the base of d 3, at the interval between 

 the diverging pairs of the fore and hind fangs of that deciduous tooth (ib. fig. 6, d 3). 

 The major part of d 4 had been broken away on the right side, but the crown remained 

 in the left maxillary. The mid link and the accessory ridge are here present, and the 

 hind surface of the second lobe shows the complex accentuation, which is further 

 carried out in the succeeding teeth. On the summits of both lobes of d 3 and d * the 

 dentine had been exposed by masticatory abrasion. 



The thin smooth partition-wall between the sockets of m 2 (the hindmost tooth in place) 

 and of m 3 was manifest at the back part of each maxillary (fig. 5, m 3), confirming, 

 with the more decisive evidences at the fore part, the homologies of the more or less 

 complete teeth, and demonstrating the immaturity of the individual from which the fossils 

 had been derived ; the usual process for exposing the premolar had the usual result. 



The crown of the premolar (ib. figs. 2, 3, 4, p 3, and fig. 7, p 3), in its antero-posterior 

 extent, resembles that of Macropus proper, not being quite equal to that of the crown of 

 the next tooth (d 4) ; but it is thicker transversely than in Macropus or Sthenurus, with a 



