96 FOSSIL JAWS OF MACROPODIDjE, 



M. giganteus, a distinct cusp separated from the lobe before and 

 behind by clefts, but connected with it by an apical link. 



Examples — -four. 



Mandibular. — The alveolar longitudinal moiety of a right ramus 

 with the first three molars, of which each is somewhat imperfect, 

 and the core of the premolar (8868); the vascular foramen is 

 well marked; the portion of the socket of the incisor preserved is 

 directed upwards at an angle of about 45° — A left premolar 

 (10216); unworn. 



Maxillary. — A left premolar (10214), unworn — A second 

 example (10215); shorter and subtriangular rather than ovate, a 

 little worn but well characterised. 



Sthenurus oreas, n.s. 



Longitudinal links of lower molars low but distinct, continuous 

 wdth the outermost of the incumbent folds which are fewer than, 

 but as broad as, in ^V. pales; posterior basal rim bulging but not 

 forming a talon. MaiicUhle thick, symphysis anchylosed, incisor 

 highly inclined, posterior dental oritice level with the teeth. 

 Upper 7nolars with rudimentary mid links continuous with the 

 innermost and largest of the incumbent folds w^hich resemble 

 those of the lower teeth but are on each face of the lobes; outer 

 mid valley closed by a marginal fold proceeding from the outer 

 end of each lobe (PL xvi. fig. 8). Upper premolar very like that 

 of S. pales, but wants the subsidiary cusp. 



Dimensions. 



Mandibular. — The full series of cheek-teeth is 62-2 in length 

 (1); the entire molar series 58*0 (1); the first three molars 41*5 

 (1); m.3 14-6 (1); the premolar 11-9 (2). The width of m.-' is 

 from 12-1 to 13 -2 (4). The anterior depth of the mandible is 

 34-2, the posterior 35-5, the thickness from 22-5 to 25-8 (2). 



Maxillary. — The first three cheek-teeth measure 42-0; the first 

 three true molars 40-2 in length; m.-, m." from 27*2 to 27'6; 



