368 STEVENSON 



forms mentioned with some Tentaaditcs. No. 8 varies little in 

 thickness and not at all in character. The upper surfaces of the 

 layers are crowded with Tentaculites gyracantJius^ which at many 

 localities are in perfect condition. No. 7 is more irregular in its 

 bedding. Thin laminae of limestones in the shales separating 

 the thicker layers are crowded with fossils, seldom in good con- 

 dition. The predominating forms are ZapJiroitis, Stromatopora, 

 Spirifer vanuxerni, Leioptcria aviculoidea, Tentaculites gyracan- 

 t/iuSy Leperditia aita, Beyriclua and minute univalves. The deli- 

 cate crinoid, Homocriniis scoparhis, is said by W. D. Gebhard 

 to belong in the upper portion of this division, but no fragments 

 of it were found. No. 6 contains many Stroinatopora, some of 

 which are large, one colony having been seen which weighed 

 more than 75 pounds. No. 4 resembles No. 7 and contains 

 the same fossils in the same condition. No. 3 resembles Nos. 5 

 and 9. It yields the Spirifer and Leioptcria well preserved but 

 Tentaculites is rare. No. 2 is very fossiliferous, and the speci- 

 mens obtained from the harder parts are very good ; StropJieo- 

 donta varistriata occurs abundantly and a fine pygidium of 

 Dalmanites viicrurus was found near the top. No. i contains 

 few fossils aside from fragments of crinoidal stems, which are 

 shown on the weathered surface. Besides the forms mentioned, 

 some of the massive beds contain Orthoceras ; no specimens 

 were found in place but several were obtained from the waste 

 piles. Irregular markings occur on the surfaces of the higher 

 beds which may be looked upon as mats of fucoids, shrinkage 

 cracks or trails ; all appear to be chafed or water-worn as though 

 the rock had been at the water's edge. 



There is no transition from the Tentaculite to the Lower Pen- 

 tamerus. The former is blue, brittle, laminated or thin-bedded ; 

 the latter is bluish gray, massive, extremely tough and refrac- 

 tory. The best blocks of Tentaculite bear little strain ; some, 1 5 

 inches thick, in the Schoharie cemetery have broken on irregular 

 foundations under the weight of comparatively small monuments, 

 but the Lower Pentamerus is reported to bear a pressure of 19,- 

 000 to 26,000 pounds to the square inch. 



