464 NEW YORK STATE MUSEUM 



transition from the typical lithologic characters of the Utica to 

 those of the Hudson. The Utica at the lower part of this exposure 

 is black with brownish streak and weathers brown to dark brown 

 with a greenish tint. It is strongly calcareous and disposed in 

 well-defined layers which usually split into laminae having smooth 

 flat surfaces. These in turn crumble to square edged fragments. 

 In some cases there are coherent layers of several inches in thick- 

 ness, quite hard and breaking with conchoidal fracture. The shale 

 in the upper part of this exposure is blackish to dark olive or 

 grayish, very fragile and weathers dirt brown. It is not sufficiently 

 calcareous to effervesce with cold acid, and is disposed in layers 

 which break up into irregular laminae with uneven rounded sur- 

 faces which in turn weather to small, thin, sharp-edged, usually 

 quadrilateral scales that readily pass into soil. No fossils were 

 found in the shales above the graptolite bed though they probably 

 contain some graptolites, and no fossils other than graptolites were 

 found in the graptolite bed. 



Conclusions 



The writer has made no special study of the Calciferous stage. 

 It is everywhere easily recognized. Its greatest thickness in this 

 region is at Hoffman ferry (section 2A) where there are 350 

 feet without reaching the base of the stage. The two lamelli- 

 branchs from no. 450 have not been identified and may prove to 

 be new species. 



The Birdseye is not difficult to recognize in this region. It is uni- 

 formly a compact, very fine grained, dove colored, dolomitic lime- 

 stone. In most cases the fossil Phytopsis tubulosa Hall is 

 rare, but in one or two places, as section 46C and the small quarry 

 on the north side of the highway two miles north of Crane's vil- 

 lage, this fossil fills the rock. If the lithologic characters of the 

 Phytopsis tubulosa horizon in section 46C be care- 

 fully studied and the basal member of the Trenton stage in the 

 other section be compared with it, there will be very little hesitancy 

 in accepting the statement that the Birdseye limestone is present 

 as a basal member throughout the region, but with variable thick- 

 ness and apparent uncomformity with the Calciferous. Its thick- 

 ness varies from less than a foot to 5 feet and is less in the eastern 

 part of the region than in the western part. 



