TEETH OF AN EXTINCT KANGAEOO. 9 



in the mandible of the adult Nototherium '. So much of the inferior surface of the 

 symphysis as is preserved in the subject of this paper is subcarinate. In the section 

 made of the fractured end the density of the bony tissue at this part is shown and the 

 absence of all trace of the primitive joint (fig. 3, s) ; the blind end of the incisive sockets 

 is shown at i i. These teeth, with their sockets, have been broken away with the rest 

 of the symphysis. 



The outer surface of the ramus (PI. II. fig. I) presents a corresponding difference of 

 conformation to tliat noted on the inner surface, in comparison with the portion of 

 mandible referred to P. azacl. Besides the minor vertical extent beneath d 4 and m 3, 

 the upper concavity and lower convexity of the outer wall are more marked. The fore 

 border of the coronoid jilate, q, rises more abruptly and at a more forward position 

 than in P. azael. 



Finally, accepting the evidence of specific distinction between the present mandible 

 and teeth and those of P. azael, the question arises whether the subject of plate cvi. 

 op. cit. has been rightly allotted to the species represented by the upper jaw and 

 teeth in plate xcvii. {op. cit.). 



The fii'st test is afforded by the penultimate grinder (i)i2) of the present fossil 

 (PI. II. fig. 4) ; it is conspicuously larger than either the tooth which precedes or that 

 which follows in the series. In the type upper jaw of P. azael m 2 is of the same 

 antero-posterior size as 7n 1 and m o ; if there is a difference, it is rather smaller. 

 I infer that the upper m 2 of the species represented by the present mandible would 

 show a corresponding proportional superiority of size as compared with m I and m 2 ; 

 and I conclude, therefore, that the portion of mandible figured in pi. cvi. oj}. cit. 

 has been rightly referred to P. azael, and that the present specimen indicates a 

 distinct species of that rare and remarkable genus. 



The original cranial fossil of Palorchestes was obtained from a freshwater deposit of 

 yellowish sand and clay with very small shells in the Province of Victoria ; its massive, 

 heavy, much petrified condition are also noted ^. 



Such is the fossilized condition of the subject of the present paper ; it was obtained 

 from fluviatile deposits in the bed of a " creek," at Gowrie, Queensland. 



The following are admeasurements of the fossil above described : — 



inches, lines. 



Length of the portion of mandible 9 



Depth below to3 3 3 



Thickness two inches below ni2 1 9 



Depth of symphysis behind incisive sockets 1 10 



Longitudinal extent of last three molars 3 7 



' Researches on the Fossil Remains of the Extinct ilammals of Australia, vol. i. pp. 259-272, pis. xxxviii., 

 xxxix., xli., xlii. 

 ' Op. cit. p. 465. 



VOL. XI. — PART I. No. 2. — January, 1880. c 



