GEOLOGY AND PALEONTOLOGY OF THE SCHOHARIE VALLEY 213 



cliffs are capped by the harder sandstones of the series and like 

 that of Vroman's Nose, are kept vertical. Higher beds of this 

 series are found in ascending the hill by the road leading east 

 from Davis Grossing. Other exposures of the Hamilton shales 

 are found in the valleys of Stony creek and the Little Schoharie, 

 and at numerous points along the lower slopes of Moheganter hill, 

 south of Middleburg. The total thickness of the Hamilton beds 

 of this region is about 1500 feet^ exclusive of the 180 feet of 

 Marcellus. The series consists mainly of sandstones and arenace- 

 ous shales, and the fossils in these beds are generally preserved 

 only in the form of molds. In the upper beds of the series 

 flagging stones are not infrequently found. 



Fossils of the Hamilton beds 



Only a few corals have been obtained from these beds, the 

 most common being Ceratopora intermedia (Nichol- 

 son) [fig. 159], composed of irregular cylindric branches, with a 

 coarse cystoid structure internally. 



Among the common brachiopods are : 

 Spirifer granulosus [fig. 160] a 

 lar£:e robust species with moderate hinge 

 area, broad rounded sinus, fold with median 

 depression and surface covered with gran- 

 ules or fine postules ; Sp. mucronatus rig. 159 ceratopora 



intermedia 



[fig. 161] generally extremely mucronate 



with a faint plication in the median sinus and a depression in the 

 fold ; C h o n e t e s c o r o n a t u s [fig. 162] , a large species 

 characterized by fine radial striae, and five or six short oblique 

 tubular spines on each side of the beak, a strong cardinal process 

 and median septum in the brachial valve ;'0h. mucronatus 

 [fig. 150], readily recognized by its coarse, rounded plications 

 and outward bending spines, parallel to the hinge area ; C h . 

 deflectus [fig. 163], a convex species with numerous fine 

 striae and abruptly outward-curving cardinal spines ; A t h y r i s 



iProsser figures out a thickness of 1685 feet for the Hamilton and Mar- 

 cellus. N. Y. State Geol. 17th An. Rep't, p. 190. 



