LOWER SILURIC SHALES OF THE MOHAWK VALLEY 43 



mile west of the Schenectady pump station, from a deep glen and a 

 long cut on the West Shore Railroad. This section is as follows: 



Feet 



I C i Covered from level of Mohawk 



river to Erie canal 25 = 25 



C 2 Fine shale which at the base of 

 the glen does not weather 

 readily to soil. Graptolites are 

 fairly abundant i TO = 135 



C 3 Very fragile shale exposed in the 



railroad cut 12 = 147 



C 4 Thin sandstone layer 2/12 = 



Cs Shale 15/12=1487/12 



C 6 Thin layer of sandstone 



C 7 Crumbling arenaceous shale 3 5/12 = 152 



C 8 Heavy layer of sandstone by the 

 highway which runs under the 

 railroad track east of the cut. . . 2 = 154 



The following fossils are recorded " from a very thin layer of 

 loose-grained, arenaceous shale exposed near the base of the rail- 

 road cut on both sides of the track and largely composed of the 

 comminuted fragments of fossils " : 



1 Triarthrus becki Green (c) 



Numerous small fragments of the pleurae and a 

 few complete specimens of the glabella 



2 Trinucleus concentricus Eaton (c) 



Mostly fragments of the spines and cheeks 



3 Plectambonites sericeus (Sowb.) H. & C. ( ?) (c) 



All the specimens are very small and rather 

 coarsely striated. 



4 Dalmanella testudinaria (Dalm.) (r) 



5 Orbiculoidea sp. 



6 Monticulipora (Prasopora) lycoperdon Say (?) (r) 



7 Crinoid segments (r) 



8 Graptolites 



Cumings (title 44, page 45,) has later described a fine section 

 exposed in a ravine on the northeastern slope of Waterstreet hill. 

 This is as follows : 



2 L Rotterdam section 



I 1 Near the railroad arch in the bottom of the creek 8 

 feet of very thin, fragile, dark grayish to bluish 

 black, argillaceous shales with occasional very 

 thin sandy layers, one near the middle of the 

 stratum being about i inch thick 8' = 8' 



