123 



DESCRIPTION OF AN ALMOST ENTIRE SKULL OF THE Thylacoleo camifew, 

 FROM A FRESHWATER DEPOSIT, DARLING DOWNS, QUEENSLAND. 



Since the foregoing pages on the genus Thylacoleo went to press I have been favoured 

 by Edward Hill, Esq., of Sydney, New South Wales, through the kind offices of his 

 brother-in-law Sir Daniel Cooper, Bart., with a small collection of fossil remains from 

 that part of the freshwater deposits of Darling Downs through which the river Conda- 

 mine has cut its bed. 



Among these fossils were parts of a broken skull, at once recognizable, by its car- 

 nassial teeth, as belonging to the large carnivorous marsupial exemplified by the subject 

 of Plate XL of the present work. 



On readjusting these fragments, I was gratified to find that they formed a more perfect 

 skull than the one which first indicated the genus and species, and not only confirmed 

 the marsupial character of the fossil, but supplied particulars of much value in deter- 

 mining the affinities of Thylacoleo in the marsupial series. 



In previously reconstructing so much of the skull of the Thylacoleo as is figured in 

 that Plate and Plates XIII., XIV. & XV. fig. 1, I had, for the facial portion there 

 preserved, only the guide of a small surface on the nasal process of a detached maxillary 

 bone which fitted to about half an inch of the fractured surface of the fore part of the 

 cranium (Plate XI. fig. 1, 73). I was glad, therefore, to have the accuracy of that "fit " 

 confirmed by the more perfect state of the skull here described. 



In comparing the upper carnassial tooth of Thylacoleo with that of Felis in the pre- 

 ceding section, I had to regret that a fracture with some loss of the tooth in the 

 marsupial carnivore prevented the precise determination of its degree of difference 

 from that of the placental feline in regard to the " tubercular " part of the carnassial ; 

 but a close inspection of the tooth in the fossil led me to infer that " little more than 

 the enamel " had been broken away (p. 111). The perfect condition of both right and 

 left carnassials at the fore part of the crown in the present instance (Plate XVII. p *) 

 enables me to state that, in the place of the tubercle, there is only a low vertical ridge 

 of enamel, about a line in breadth, without any additional inner root at the fore part 

 of the tooth: the large carnassial of Thylacoleo consists exclusively of the "blade." 

 This is more worn than in the original specimen described. A smooth and polished 

 surface is exposed by attrition, sloping from within downward and outward, and meeting 

 the inwardly bent outer enamelled surface at an angle of about 50°. The worn surface 

 is deeper at the fore and hind parts of the tooth than at the middle, agreeably with 

 the antero-posterior concavity of the outer surface. The hindmost part of the worn 

 surface, which is 4 lines across, slopes rather outwardly from the rest, at a low angle 



3 



