University of the State of New York 



New York State Museum 



Frederick J. H. Merrill Director 

 John M. Clarke State paleontologist 



Bulletin 49 December 1901 

 PALEONTOL0GIC PAPERS 2 



TRENTON CONGLOMERATE OF RYSEDORPH HILL 

 RENSSELAER CO. N. Y. AND ITS FAUNA 



BY RUDOLF RUEDEMANN 



INTRODUCTION 



From the Rensselaer plateau, which lies on the east side of the 

 Hudson river opposite Albany, and extends from the river plain 

 to the foot of the Taconic mountains, rise a number of ridges 

 trending in a north northeasterly direction. The first of these 

 passes only about one mile east of the city of Rensselaer. It is 

 broken into several hills which, standing out in bold relief from 

 the plateau, are veritable landmarks and can be seen for a great 

 distance on both sides of the river. One of the more conspicuous 

 of these hills is known among the people of the neighborhood by 

 the appropriate name, " The pinnacle." It can be seen from the 

 streets of Albany and readily attracts attention by its steep .slopes 

 and its abrupt elevation above the plateau. On the northern 

 brow of the hill projects a mass of very hard limestone con- 

 glomerate which, having evidently protected the underlying soft 

 shales from the action of ice and weather, is in some measure the 

 cause of the existence of the hill. A closer investigation of this 

 conglomerate, combined with observations on conglomerate beds 

 farther south in the strike of this bed, has revealed not only 

 the presence of a very interesting fauna but also the notable 

 fact that the pebbles composing this bed vary greatly in their 



