BONE CAVE AT PORT KENNEDY. 



283 



parrying cut (fig. 10), copied from his figure published in the Journal gJ Science 

 and Arts, 3rd Series, Vol. I, p. 237. 1 



The chasm which primitive man would have avoided as a habitation was, 

 we may suppose from the drawing, an abyss, edged with shale crusts, twenty 

 to thirty feet in diameter at the mouth, and at least fifty, probably sixty or 

 seventy feet deep, with descending walls sloping inward : a well-like hole, down 



which the flood of an inundation, 

 overwhelming the hill-top, would 

 have tumbled like a waterfall 

 (fig. 11). 



To the largest mammals the 

 place would have been inaccessi- 

 ble. Unable to reach its bottom 

 alive they could not have ventured 

 thither as animals sometimes enter 

 caves, to die. On the other hand, 

 granting the ability of the mice 

 and many of the smaller rodents to 

 ascend and descend the walls, the 

 evidence all indicates that even 

 they were forced into the death 

 trap with the rest and perished 

 with them. Had they crawled 

 down the perpendicular sides, had 

 they entered through lateral fis- 

 sures so as to have been present 

 alive at the time of, or soon after 

 the death of the others, traces 

 of their gnawings should have 

 been found on the bones, but the 

 absence on all the specimens of these unmistakable tooth marks, so often recog- 

 nized upon cave remains, was one of the striking characteristics of the fossils. 



That the general fate of so many creatures had been a sudden and common 



Fig. ll.-THE PORT KENNEDY BONE CAVE. 



East and west cross-section of the south end of Erwin's quarry 

 (not drawn to scale, for the sake of clearness), showing in the 

 shaded parts A, B. C, D the probable original shape, size and rela- 

 tive position of the chasm. The continuous dotted line shows the 

 area of rock and debris, and a portion of the original cave at 

 present removed by the blasting and excavation of limestone at 

 the quarry. 



The lined shading at. A shows the probable portion of the con- 

 tents of the chasm removed by Wheatley in 1871. 



The lined shading at B shows the part of the contents of the 

 chasm removed by Dr. Dixon and Mr. Bhoads in 1874. 



The cross shading at. C C shows that part of the contents of the 

 chasm removed by ourselves in 1894, '95, '96. 



The doited shading at D, D, D shows the position of the contents 

 of the chasm still remaining at the site. 



The lowest continuous dotted line marking the quarry floor is 

 at the level of the neighboring river. The excessive and increas- 

 ing influx of water at the point marked by the lower letter C, 

 threatening danger to the quarry, prevented further digging in 



1 The drawing below the point B shows that he considers that the bottom of the fissure had not been 

 reached, though he does not say so. But granting the intrusion of the remains from the surface, his presenta- 

 tion of a crust of triassic shale, resting like a flat roof directly over the chasm and its contents, is probably imagi- 

 nary. The shale crust doubtless existing at the spot, and still seen capping the limestone escarpments near by. 

 must have been worn away or broken in immediately over the chasm when Wheatley saw it. His depth of 

 forty feet is likewise improbable, notwithstanding irregularities in the surface, since the quarry floor of 1871 (a 

 portion of which still remains), then represented the bottom of his exposure (and the present top of ours is not 

 more than 30 to 33 feet below the original level of the hill-top). There are evidences of constriction, however, 

 in the fissure walls at the top of our exposure, where I found protruding crusts of rock much shattered by blast- 

 ing, arching inward, and where the general configuration seemed to account for the narrowed outline of Mr. 

 Wheatley's drawing at the depth of his horizontal dotted line marked " 10 feet." On the whole, his contours as 

 illustrated in the figure, probably the result of guessed measurements, do not affect the more important question 

 of the general configuration of the chasm, which he has fortunately preserved for us, and there seems no reason 

 to doubt that we are at present at work in a portion of it below his stratum B and his 10-foot line. At our point 

 of exposure the chasm had again widened to 25 feet, a state of affairs which 1 attempt to illustrate in the chart 

 (fig. 11). 



