214 C. S. Prosser — Devonian System 



tant to recall the known limit of the eastern extension of the 

 Tully limestone of central New York, which formation was 

 found by Yanuxem in Chenango county " at the northwestern 

 part of Smyrna, on the road to DePuyter village, where the 

 road crosses the west branch of the Chenango [river]."* In 

 the summer of 1886 the writer studied this region, and near 

 Upperville in Smyrna township reported limestone layers 

 separated by calcareous shales, twenty-five feet in thickness, f 

 Farther east in the Unadilla valley no representative of the 

 zone was found. 



One fourth mile farther north than the outcrop of the cal- 

 careous, coral zone, the highway crosses Brodhead creek and 

 under the bridge and along the banks of the stream are 

 exposures of rather finely arenaceous, bluish shales which are 

 moderately fossiliferous. This zone is easily traced in the 

 field on account of its being composed of thin, dark-colored 

 shales which succeed the coarse arenaceous shales of the 

 middle and lower Hamilton. One of the best localities for 

 collecting fossils in this zone is in the gorge of the Sawkill 

 creek, above Milford, Pike county, and the fauna of that 

 station will be given for this horizon. (See fauna of No. 14767 2 .) 



The outcrop from which this fauna was obtained is one 

 of the typical exposures of this zone, which was referred 

 by Professor White to the Genesee shale. The fossils came 

 from the upper part of the zone as exposed in the gorge of 

 the Sawkill, which "rapidly excavates a long narrow canon 

 out of the Genesee shale"^. While under the description of 

 the geological formations, Professor White says that " the top 

 of the Hamilton is marked off everywhere in this district by 

 the appearance of a dark sandy fossil slate or shale, which 

 seems to be identical with the Genesee black slate of the New 

 York Reports."§ 



A geologist familiar with the Genesee shale of central and 

 western New York will find some difficulty in correlating 

 this zone with the New York Genesee. These shales have 



* Geol. New York, Pt. III. 1842, p. 292. Also, see p. 164. 



f Proc. Am. Assoc. Adv. Sci.. vol. xxxvi, 1887. p. 210. 



$G 6 , p. 199. 



^IMd.. p. 107. Professor Lesley called these shales Genesee in the explana- 

 tion of the geological structure of Monroe Co., Report X, 1885. p. lxxx. 



Mr. Arthur Winslow in his work along the Lehigh river named the continua- 

 tion of these shales Genesee, and mentioned them particularly at Weissport (Ann 

 Rept. Geol. Surv. Penn., 1886. Pt. IY, pp. 1365, 1367, 1371). Also, see Winslow's 

 map and section from exposures along the Lehigh river, sheet No. 3. In the 

 continuation of the Lehigh section down the river by Mr. "Frank A. Hill, similar 

 shales are called Genesee (Ibid. pp. 1373. 1374). A considerable collection of 

 fossils was made from near the Weissport station of the Central Railroad of New 

 Jersey, and from the R. R. cut above Bowmans; the lithologic character of the 

 shale and the fauna is about the same as in the exposures of the same zone 

 farther northeast in Monroe and Pike counties. 



