216 C. S. JProsser — Devonian System 



very little lithologic resemblance to the Genesee and the list 

 of fossils given above shows that the fauna is not that of the 

 Genesee, but rather one of the Upper Hamilton stage. Only 

 one species of the list identified from the upper shale of the 

 Sawkill canon has been reported from the Genesee shale of 

 New York, viz : Amboccelia umbonata (Con.) Hall.* 



In central New York the Genesee shale does not extend 

 much farther east than the Tully limestone. Near Smyrna 

 the writer found black, argillaceous shales some twenty feet 

 in thicknessf and Vanuxem reported it farther east at North 

 New Berlin,;}; now New Berlin. In 18^3 the exposures along 

 the valley of the Unadilla river to New Berlin and then 

 across the hills to Oneonta were carefully studied ; but no 

 evidence was found of the Genesee black shale or its fauna. 



The rather fissile Genesee (?) shales are succeeded by coarser, 

 arenaceous shales alternating with sandstones of moderate 

 thickness. The sandstones are slightly greenish-gray in color, 

 quite micaceous and in lithologic appearance decidedly dif- 

 ferent from the darker and more argillaceous shales below. 

 Fossils are not common in this zone, but occasionally occur 

 abundantly in thin layers. In the ledges along the hill-sides 

 east of the highway, and by the side of the county road, just 

 above the D. L. & W. R. R. crossing, about one-half mile 

 south of Spragueville, are exposures of these arenaceous shales 

 containing fossils. 



The fauna of No. 1475 C 6 - 7 ' and8 is as follows : 



1. Palmoneilo plana Hall . (a) 



2. JVaculites oblongatus Con . . (a) 



3. Palceoneilo emarginata, (Con.) Hall (?) var (e) 



5. Spirifera mesastrialis Hall (c) 



6. (?) Actinopteria cf. Boydi Hall (c) 



7. Nnculites cf. cw/eiformis Con (c) 



8. Prothyris lanceolata Hall . . (r) 



9. Microdon (Cypricardella) gregarius Hall (r) 



1 0. Spirifera mesacostalis Hall (r) 



1 1. Orthonota (?) parvula Hall (?) (rr) 



1 2. Nucida corbuliformis Hall _ (rr) 



13. Tropidolepius carinatiis (Con.) Hall (rr) 



14. Uomalonotus De Kayi (Green) Em (rr) 



15. Leptodesma Roger si Hall (?) (rr) 



The rocks from which the above fauna was obtained are a 

 typical exposure of those which have been called Chemung by 



* Dr. J. M. Clarke in 1885 gave a list of fifty-five species that had been found 

 in the Genesee shale of New York (Bull. U. S. Geol. Surv., No. 16, pp. 33, 69, 

 70). To this fauna he has since added additional species ; see, Am. Geol., vol. 

 viii, August 1891, pp. 88-91. 



f Proc. Am. Assoc. Adv. Sci., vol. xxxvi, p. 210. 



X Geol. New York, Pt. Ill, p. 292. 



