SIXTH REPORT OF THE DIRECTOR I909 I9 



occupied by the cherty beds along the Spackenkill road. The 

 thick masses in the Stoneco quarry have not yielded fossils. It 

 seems that within this western strip there is a considerable 

 thickness of heavy dolomitic limestones lying above the Upper 

 Cambric fossiliferous beds which are older than the Beekman- 

 town C Calciferous," Rochdale group). Whether this mass 

 belongs with the Cambric of the Canadian group could not be deter- 

 mined, nor the question of whether deposition was continuous 

 from one period to the other. 



During the seasons of 1908 and 1909 a number of new cuts 

 were opened in the . Fishkill limestone in the process of con- 

 structing the State road from Fishkill Landing to Beekman. 

 These were examined with considerable care, but except for one 

 or two doubtful cases, no fossils were discovered. A mile west 

 of East Fishkill (" Gayhead ") a slightly distorted impression 

 with form suggesting some member of the Strophomenidae was 

 found on the freshly broken rock. All shell characters were 

 absent, although the form was reasonably distinct. 



Fossils which could be recognized have been discovered in 

 this limestone along its western margin, in the Lower Cambric 

 horizon, as above described, and in one instance along its north- 

 ern margin near Hopewell. Elsewhere they have not been found 

 either on fresh surfaces or in weathered outcrops. 



The slate formation is almost completely eroded from this 

 limestone mass. There is reason for thinking that much of the 

 limestone is older than the Trenton and perhaps of Cambric or 

 early Ordovicic age. 



Hudson River slate formation. A careful examination of many 

 outcrops in this formation has added only one new fossil locality. 

 This occurs at a hamlet known as Swartoutville, about 2^ miles 

 north of Brinckerhoff. The fossiliferous ledges were discovered 

 while tracing the limestone boundary. On the farm of Irving Hitch- 

 cock at Swartoutville, about three or four hundred yards west of 

 the road from Brinckerhoff to Hopewell Junction, is a high knoll 

 made up of gray limy shales with interbedded limestones. The 

 shales contain P 1 e c t a m b o n i t e s s e r i c e u s and other fos- 

 sil fragments. These beds are regarded as lying near the base of 

 the slate formation and as of probable Trenton age. The beds ap- 

 pear structurally to belong with the limestone which is faulted 

 against the presumably younger slates on the west. 



Considerable interest attaches to the discovery of several 

 small, usually conglomeratic, limestone patches within this 

 formation. Three of these occur near Arthursburg north of 



