50 BONE BRECCIA DEPOSIT, 



the form agrees with the smaller Wallabies and Rock-Wallabiess 

 and differs from the larger sorts. 



Though the form thus equals in size the larger Wallabies, its 

 affinities are probably more with the smaller sorts, and in some 

 respects it seems to come very near to the Rock-Wallabies 

 (Petrogale). 



The following are some of the principal measurements : — 

 Depth of mandibles behind p* (4 sp.), 17, 18, 184, 18-4 mm. 



„ infrontofm* (3sp.), 154, 16-9, 16-9mm. 

 Length of p* (2sp.)... 6'8 mm. (worn), 74mm. (unworn). 



„ m^-m- (2 sp.)...134, 13-5 mm. 



m^-m"' (2 sp.)...21-8, 21-9 mm. 

 ,, m"-m* (2sp.)...25, 26 mm. 



m^-m* (3 sp.)...29-2, 30-8, 314 mm. 

 m-''-m* (3 sp.)...17-8, 18-, 18-8 mm. 

 p*-m-^ (3 sp)... 36-5, 37, 374 mm. 

 Width of nr^ (3 sp.)...5-7, 5-8, 5-8 mm. 

 Thickness of mandible below nr"*, 9-3 mm. 



PoTOROUS TRiDACTYLUS, var. ANTiQUUS, n.var. 



In the deposit are the remains of a small Potorous. Though 

 not abundant a numljer of specimens have been obtained. As I 

 have been unable to obtain a skull of the existing Potorous 

 tridactylus I am in some doubt as to the exact position of the 

 fossil form. Polorous tridactylus, as defined by Thomas, is 

 apparently a very variable species, and it seems probable that the 

 fossil form is but a variety. As regards the premolar of this 

 species Thomas (Brit. Mus. Cat. Marsup.) sa3'^s: — "P^ very variable; 

 in the large Tasmanian form {' apicalis ') 7 or 8 millim. long, with 

 four distinct grooves; in the smaller New South Wales examples, 

 and in the still smaller Tasmanian form described as ' rufus ' 6 or 

 7 millim. long with only three grooves." In the fossil form the 

 upper premolar measures 64 mm., but has four grooves. The 

 three anterior grooves are well marked, but the fourth, thougli 

 well marked at the edge, does not extend so far up the tooth as 

 the others. In the deciduous p^ there are but three grooves. In 

 the lower p* there are four grooves, all well developed. 



