126 Report of the State Geologist. 



XIX F i . On the western side of the small valley formed by Herrington 

 brook and to the northwest of the " coal mine " is a steep hill 200 feet higher. 

 Near the top of the hill is Mulligan's quarry, from which bluish, fine-grained, 

 thin flagstones are produced. Most of the layers are only from one-half to 

 two inches thick, but the workmen claim that if well bedded they do not 

 break easily, and the flags have been used to some extent in the village for 

 sidewalks. Above the flags in the quarry are rather coarse, irregular shales, 

 which contain fossils ; Idorhynch us mesacostaHs, Hall, and Spirifer are common. 

 This quarry is barometrically about 455 feet above the railroad station in 

 Sherburne, or approximately 1,500 feet A. T., and is considered as belonging 

 to the lower part of the Ithaca group. The hill is composed of the Sherburne 

 and Ithaca formations, and has been so represented on the geologic map. 



XIX I> 1 . In the eastern part of Sherburne village is a stream known as 

 Mad brook, which has rocky banks for a mile or more. At the head of the 

 glen is Sherburne or Rexford falls, a local summer resort and picnic ground. 

 The rocks along the side of the brook contain numerous fossils, making an 

 excellent locality for collecting species found in the upper part of the Hamil- 

 ton formation. The lowest exposures of rocks in Mad brook are in the edge 

 of the village, only thirty-two feet, by the level, above the railroad, or with 

 an altitude of 1,074 feet A. T. They are thin, blue shales, that split very 

 finely, contain numerous fossils and some calcareous layers, composed princi- 



pally of fossils. The observed fauna is as follows : 



1. Orthis Va?iuxemi, Hall. (c) 



2. Aihyris (Spirigera) spiriferoides (Eaton), Hall. (r) 



3. Stropheodonta perplana (Con.), Hall. (r) 



4. Stropheodonta inequistriata (Con.), Hall. (a) 



5. Spirifer mucronatus (Con.), Bill. (a) 



6. Spirifer granulosus (Con.), Hall and Clarke. (rr) 



7. Spirifer audaculus (Con.), Hall and Clarke. (rr) 



8. Spirifer fimbriates (Con.), Bill. (rr) 



9. Orthothetes Chemungensis (Con.), Hall and Clarke. (rr) 



10. Chonetes coronata (Con.), Hall. (r) 



11. Centronella impressa, Hall. (?) (r) 



12. Ti'0]>idole}>ttis cariiiatus (Con.), Hall. (c) 



13. Orbiculoidea sp. (rr) 



14. hmgula (portion of a valve). (rr) 



15. Nucuhi I>«1] istriiita (Con.), Hall. (rr) 



16. Macrodon JIamiltoniw, Hall. (c) 



