778 
PROFESSOR OWEN ON PORTIONS OF 
The largest of the portions of the tusk (Plate 51, figs. 1-4) is from near the base, and 
includes part of the pulp-cavity, p. 
It is 5 inches in length, of a full elliptical, almost circular shape transversely ; 
measuring across at the larger end (fig. 3), 2 inches 6 lines by 2 inches 5 lines; at the 
smaller end (fig. 4), 2 inches by 1 inch 10 lines. The diameters of the pulp-cavity are, 
at the larger end, 1 inch 1 line by 1 inch ; at the smaller end, 6 lines by 5 lines. 
The thickness of the wall of ivory, at the larger end, varies from 8 to 9 lines, and is 
the same at the smaller end, not decreasing in the ratio of the pulp-cavity. 
In this portion of tusk the outer or cemental layer and much of the outermost 
layer of dentine are lost. In the smaller portions of the tusk, where the cemental 
layer is preserved, it has a smooth outer surface ; that of the dentine which is exposed 
shows the shallow longitudinal linear impressions which may be seen in that part of 
the tusk of most Elephants recent and fossil. The transversely fractured surfaces 
present the decussating curvilinear lines characteristic of true or Proboscidian ivory ; 
but they are more minute than in the tusks of the African or Indian Elephants. 
The dentine has, also, the compactness of ivory, and reveals the microscopic characters 
presently to be described. The longitudinal linear impressions on the outer layer 
of dentine are of varying, but nowhere of great depth, mostly alternating in this 
character. The deeper lines run along with interspaces of from i to ^ an inch, and 
such defined longitudinal tracts are commonly impressed by a fainter line running 
along or near their middle. A tract bounded by the deeper lines, half an inch in 
breadth, shows two of the shallower longitudinal impressions. The general surface is 
smooth and polished ; the inner surface, toward the pulp-cavity, is smooth. 
The present portion of tusk shows a slight departure from straightness; a degree of 
curvature is more evident in the second, rather narrower but longer, portion (ib., figs. 
5, 6). This portion is 6^ inches in length, 2 inches 1 line by 2 inches in thickness at 
the largest end, 1 inch 10 lines by 1 inch 9 lines at the smaller end (ib., fig. 6). The 
inner layers of the dentine at the larger end have been too much and irregularly 
broken away to indicate satisfactorily the size and termination there of the pulp cavity ; 
but three inches in advance the tusk is solid, and the same absence of pulp-cavity is 
shown at the smaller end, where the final consolidation is indicated by a dark spot. On 
the surface of this portion of tusk, where the cement is wanting, the longitudinal 
lineation of the outer layer of dentine has become fainter. 
The third portion (ib., figs. 7, 8) is from near the apical extremity of the tusk ; it is 
solid and the outer layers of dentine, coated by the smooth cement, are partially 
future enterprise lead travellers to that quarter, it will be deserving their while to push the enquiry 
further and add more evidence regarding the existence of the Mastodontoid animals of New Holland.” 
— £ Physical Description of New South Wales and Van Dieman’s Land,’ 8vo., London, 1845, p. 312. 
Subsequent unintermitting correspondence in relation to discovery and acquisition of Australian fossil 
remains have failed to bring to my notice any evidence of a Proboscidian Mammal before the reception of 
the subjects of the present communication. 
