GEOLOGY AND PALEONTOLOGY OF THE SCHOHARIE VALLEY 195 



nearly 100 feet are exposed in successively outcropping ledges 

 above the Esopus shales. At Borst Mills, a mile above Middle- 

 burg, the Onondaga crosses the Schoharie kill, producing a low 

 fall with ledges visible along the bank. 



Fossils of the Onondaga limestone 



A complete list of the Onondaga fossils found in the Schoharie 

 region is given in chapter 7. A few of the more characteristic 



may be noted here. Of the corals 

 making up the reefs, only a few 

 are cited here and in the list, 

 since no complete study of the 

 coral fauna of the New York 

 Onondaga has been made. The 

 following are abundant : F a v o - 

 sites basalticus [fig. 121, 

 122], most readily recognized 

 by the single, rarely double, row 

 of large mural pores in each wall 

 of the coral lite s ; F . epider- 

 matus with two or more rows 

 of mural pores on each face of 

 the corallite separated by faint 



elevated ridges ; Zaphrentis prolifica [fig. 123] , a 

 short curved, hornlike species with the septa slightly twisted at 

 the center ; Cyathophyllum robustum, a large, 

 robust, cylindric species with numerous thin septa and an abun- 

 dance of dissepimental tissue. With these occur several species 

 of Dendropora, slender, more or less cylindric and branching 

 stems with the corallites opening in circular or oval apertures 

 superficially far apart. 



Among the brachiopods the following may be noted : Ortlio- 

 t h e t e s pandora [fig. 124], a reversed strophomenoid shell, 

 slightly unsymmetric, with the pedicle valve moderately concave 

 anteriorly and with radiating striae increased by intercalation 

 and crenulated by concentric striae; Le p t a e n a r h o m - 



Fig-. ]26 Stropheodonta 

 inequiradiata 



