62 AUSTRALIAN QUATERNARY CLIMATES AND MIGRATION 



thick (Plate 2, Fig. 11). Another piece (Plate 2, Fig. 10) of a 

 lower incisor, 120mm. long, with a longer diameter of 45mm. and 

 a shorter one of 33mm. exhibits on its outer surface fine incisions 

 and a gash or two. A lower incisor, broken across, shows at one 

 end a fairly smooth, wind-polished cross-section, and at the other 

 end, a very irregular one. The smooth section is due to a break 

 made soon after the death of the Diptrotodon, for it shows 

 numerous, shallow incisions made by the teeth of some small pre- 

 datory animal when the incisor was green. The irregular cross- 

 section at the other end is due to a break that occurred some time 

 after death, and seemingly before the tooth was buried by 

 deposition. The smaller diameter of the incisor is 1-25 in. and it 

 was too massive for any animal to bite through. It is difficult to 

 account for either of the breaks unless they were the work of man. 

 That he was in the district at the time is shown by the occurrence 

 of the Pejark Marsh Millstone in a bed below the bone bed. 



Spencer and Walcott came to the conclusion in regard to the 

 Buchan Bone that "in the absence of definite proof, that man 

 was [not] at any time an occupant of the cave in which the Buchan 

 Bone was found, and the cuts were made by Thylacoleo. } ' 



The bone fragments from Salt Creek, Normanville, South Aus- 

 tralia, showed mostly straight, blunt gashes, a few the character- 

 istic curve of the cuts of the Pejark Marsh bone fragments, but no 

 example of the clean cuts right through the bones as at Pejark 

 Marsh. They concluded that here too, all the cuts could have been 

 made by Thylacoleo. 



The cuts on the Myall Creek fragments from New South Wales 

 are ascribed by De Vis to Thylacoleo ; here again the clean cuts 

 right through the bones are absent. 



The Colongulac Bone was picked up on the shores of Lake Colon- 

 gulac, about 10 miles E.N.E. of Pejark Marsh. The cuts (Plate 2, 

 Fig. 9) are quite different in shape to any at Pejark Marsh. 

 Spencer and Walcott state that they were made on the 4th meta- 

 tarsal probably of the extinct Palorchestes and consist of two, 

 deep, wredge-shaped notches extending a little more than half way 

 across the bone. The greatest width of one notch is approximately 

 ] 2mm. and that of the other about 10mm. Where the two notches 

 are confluent on the margin of the bone, it has been penetrated to 

 a depth of 6mm. The notch in the dorsal surface is, as nearly as 

 can be measured, 10mm. in depth, compared with 6mm, in the 

 case of the ventral one. Spencer and Walcott give the facts 

 concerning the finding of the bone and accept its authenticity. 

 They compare the gashes to one of the Myall Creek fragments 



