BY C. W. DE VIS. 127 



side of the middle of its edge, the mid-point being the termination 

 of a rib on the outer side; the intero-posterior cusp is as yet 

 obscurel}^ defined; in a somewhat older example the crown is 

 thickened and rounded at each end, two ribs appear on the outer 

 side, and the intero-posterior cusp is more distinct; when near 

 emergence the tooth gains greater robustness, and the cusp 

 becomes exserted from the lobe. 



Molars (PI. xviii. fig. 9) undistinguishable from those of M. 

 magister. 



The undulation of the lower contour line of the mandible is 



well marked. 



Rise and fall of teeth. 



Of this little is known; p.* is newly arisen, and p."^ is not 

 entirely up when the hind lobe of m. ^ is coming into use; by the 

 time that the hind lobe of m."* gets into w^ear, p."*^ is moderately 

 worn and procumbent, whence we may infer that it is thrust out 

 soon afterwards while still serviceable. 



Exa. inp les — -fifty -fovr. 



These include besides the young maxilla forming the type — 

 Four adult maxillae; two with premolars, and all with m. ^ among 

 the teeth preserved; twelve others in which m. ^ shows its cha- 

 racteristic more or less perfectly : one with m.^, m.*;one with m.'^; 

 and one with m.* referred to the species merely on account of 

 similarity of size. 



In four adolescent mandibles the well-preserved premolars 

 alone effectually prevent the molars behind them being ascribed 

 to M. magister, as they might otherwise have been on seemingly 

 sufficient grounds, and well illustrate the folly of positively 

 identifying kangaroo mandibles by molars only. Twenty-seven 

 others are provisionally determined by the dimensions of the 

 teeth. 



Macropus faunus, n.s. 



Molars wdth curved crests, rounded angles and strong links. 

 Upper premolar tricuspid, without ledge on the inner side, but 

 with an intero-posterior member simulating the corresponding 



