502 



garoo. The distal end is more expanded, surpassing the proximal end in breadth. 

 The ridge on the back part of the shaft (ib. fig. 1, 6) is broader, less produced, and less 

 extended downward than in Macropus, Protemnodon, or Palorchestes. 



The well-preserved proximal end of the fifth metatarsal shows its apophysial pro- 

 duction (ib. figs. 1 & 2, z) proximad of the articular surface of the fourth metatarsal. 

 This process is absolutely as well as relatively longer than in Palorchestes Azael. As 

 in that species three articular facets are present at this end of the bone, two for the 

 cuboid and one for the contiguous (fourth) metatarsal, the cuboidal surfaces being 

 relatively larger than in Palorchestes, and the tubercle projecting tibiad beyond the 

 metatarsal surface is more developed in Procoptodon. 



At the distal articular surface the chief difference is seen in the greater production 

 of the tibial convexity of the trochlea. By reason of this prominence its preservation 

 is rare in the rolled fossils of the present form of metatarsal from the creek-beds of 

 Queensland. 



Of the metatarsals of this shorter type three modifications are shown by the fossils 

 that have reached me, which are indicative of three species of Procoptodon. The 

 metatarsal (Plate CXIX. figs. 10-12), of equal length with that (ib. figs. 1, 2) of Procop- 

 todon Pusio, but more slender, I take to be from a female Kangaroo of that species. 



Deeming it probable that the form (family or genus) of Macropodal Marsupials 

 which, by dental and mandibular characters, offered the nearest approach to the large 

 isopodal or gradatorial family (Diprotodontidae) would present a corresponding approach 

 thereto in the form and proportions of the hind foot, I refer the present type of meta- 

 tarsal bones to the genus Procoptodon. 



In this genus the above-described representative of the smallest known species would 

 answer, as to size, to the evidences which have been given of the maxillary, mandibular, 

 and dental characters of Procoptodon Pusio (p. 454, Plate XC. figs. 2, 7). 



The specimens next in size (Plate CXIX. figs. 6-9) I refer, on similar grounds, to 

 Procoptodon Rapha (p. 457, Plate XC. figs. 8-12). 



Parts of a hind foot of a still larger species similarly relate to Procoptodon Goliah 

 (p. 4G0, Plate XCIV.). 



The fourth metatarsal (Plate CXXI.) is 6 inches 3 lines in length, with a proximal 

 breadth of 1 inch 8 lines, the opposite dimension being 1 inch 5 lines. The fore part 

 of the cuboidal surface is relatively broader from before backward than in Procoptodon 

 Pusio. There is no indication of the proximo-tibial ridge, in which character the 

 present bone resembles its homologue in Procoptodon Pusio (Plate CXIX. fig. 2,/r). 



The posterior angle at the proximal half of the shaft is less marked and less produced 

 than in Procoptodon Pusio. The posterior depressions above the distal trochlea are 

 deeper and better defined than in Procoptodon Rapha or Procop. Pusio. 



The fifth metatarsal of Procoptodon Goliah (Plate CXVIII. figs. 8-11) is 5 inches in 

 length ; the greatest diameter of the shaft is 1 inch, equalling that of the homologous 

 bone in Palorchestes Azael, which is more than one fourth longer. The tibial convexity 



