4 NEW YORK STATE MUSEUM 



ajifo. This lonj^lomerate bed is intercalated in the so called iiud 

 Bou river shales discussed in a previous pajier and is thus of still 

 farther interest in its bearinj; on the question of the age of those 

 shales. 



A perusal ol llie early lueraiure ot the ^ew iurk geologic sur 

 vey leaves no doubt that this same hill with the capping limestone 

 conglomerate once played a very interesting and important role 

 in the bitter struggle over the Taconic problem. 



Dr Emmons was pi'obably the first to notice the locality and 

 collect it<!» fossils; for Hall, in Palcontologi/ of Xcic York, 1:3."), 

 described among the Chazy fossils a cephaloi)od as O r t h o- 

 c e r a s b i 1 i n e a t u m , and added : 



An examination of this specimen since the plate was engraved 

 convinces me that it is identical with O. b i 1 i n e a t u m of the 

 Trenton limestone. This specimen was given me by Dr Emmons 

 as coming from the Calciferous sandstone at a locality 2 miles 

 east of the city of Albany. An examination of the spot has con- 

 vinced me that the rock in question is the Trenton limestone 

 thrust up through the Hudson river slates. The association of 

 fossils as well as other circunifitances prohibit its reference to 

 the Calciferous sandrock. 



Dr Emmons, in his endeavor to defend the Taconic system 

 against the aggressions of nearly all his contemporaries, con- 

 sidered the stratigraphy of this locality as of special importance 

 for the demonstration of his assertion that the Siluric beds lie 

 unconformably on the Taconic. In his last defense of bis 

 cherished ol)ject of research, contained in Amcricau f/eologi/, 1855, 

 pt 2, p. 72, a section of Rysedorph hill^ is given, which is copied 

 here with the following description of the stratigraphic relations. 



At the milldam, the blackish sandstones of the Hudson river 

 dip also east; half a mile further sandstones again crop out, 

 dii>ping stee|)ly to the west. Just beyondj'iyjj green Taconic 

 slates dipping e 10'^ s support a heavy mass oFCalciferous sand- 



1 Dr Emmong calls the hill Cantonment hill. Inquiries among the occupants of the neighboring 

 farms brought out the fact that the next hill succeeding In southerly direction was formerly called 

 Cantonment hill on account of u military encampment on It during the war of 1812, ami this term has 

 now J»ecn perverted into Catamount hill, the present name of that prominence; while the hill 

 denrrlbed by Dr Emmons )>a.sBes now under various names, as Su^ar Loaf hill, the Pinnacle, Ryse- 

 dorph hill, etc. Ah the last name has been adopted on the topographic map of the U. S. treologlc 

 survey, it id retained in this paper, though no longer In popular use. 



