I»8 NEW YORK STATE MUSEUM 



cave, as we shall call the one we are here discussing, there is 

 a similar wedge-shaped mass but toward the front of the cave 

 the edge of this wedge was uppermost. There is some evidence 

 in this cave that solution began its work on two nearly parallel 

 fissures which were about a meter apart near the top of the 

 cliff but which increased this distance to a little more than 2 

 meters in descending to the present low water level of the lake. 

 This partition was subsequently cut away in many places. 

 Dentpit action is at work cutting through the separating walls 

 of smaller contiguous caves. Portions of these former sepa- 

 rating walls are now left as pillars supporting the roof of a 

 widened cave mouth. This cave has two items of proof to offer 

 concerning its age, which differ from any we have yet mentioned. 



Plate 2,2 shows a portion of the east wall of this cave in the region 

 of the sinkhole. At (a) we have a portion of the older face of the 

 wall removed by the action, of expanding water in joint planes. The 

 surface thus exposed is not a fresh one but has been subjected to 

 a long period of weathering. We may note a still older sur- 

 face of similar character under the overhanging mass at the right. 

 At (^) we have what we may call an original surface or one not 

 yet acted upon by the agent specified above. The deep etching 

 which the edges of the very irregular bed surfaces have received 

 and the much weathered edges of the finer laminae both speak of 

 very great age, for the position is here a sheltered one. At (c) we 

 have a portion of the wall of a cylindrical excavation which 

 appears to have been cut by spirally descending waters. This 

 cylinder opened into a basin which was more deeply cut in the side 

 wall and which plainly speaks of water carrying abrading tools. 

 Note also a portion of the deeply cut basin diagonally above this 

 at the right which also emptied into it. Is any agent so cutting 

 these walls at the present time ? One answer to this question is to 

 be found in the filling of this part of the cave for this filling has 

 covered up a large portion of the lower basin and this it could not 

 have done were any such cutting action now present. The .filling 

 is talus like and neither depO'sited nor modified by runmng water. 

 Another answer and yet the same, is to be found in the appearance 

 of the surface at (c) which shows its etched, irregular bed edges 

 and its laminae nearly as plainly as at (Z?). The slight difference 

 between these two surfaces is due to the fact that the recessed 

 surface at (c) is now better protected, from even getting wet, than 

 is the surfa,ce at (/;). The very slight drainage this cave may now 

 receive from rainfall or melting snows has had nothing whatever 



