GEOLOGY OF THE WATKINS AND ELMIRA QUADRANGLES 



15 



occur in the shales and on the lower surface of one of the sandstones : 

 Manticoceras pattersoni, Orthoceras sp., Phrag- 

 mostoma n a t a t o r , P . i n c i s u m , P a 1 a e o n e i 1 o 

 f i 1 o s a , N u c u 1 i t e s o b 1 o n g a t u s , N. cf. cunei- 

 formis, Grammysia sp. ?, B u c h i o 1 a speciosa, S c h i z o- 

 phoria imp res s a , Orthis tioga, Chonetes 

 s c i t u 1 u s , P r o d u c t e 1 1 a spinulicosta. They are not 

 abundant here and were not found at other exposures of this 

 horizon. 



West Hill flags and shale 



This division here attains a thickness of 315 feet. Its rocks con- 

 sist of numerous thin, uneven flags 2 to 4 inches thick and occa- 

 sionally compact even blue sandstones 6 inches to 1 foot, 6 inches 

 thick, separated by dark soft bluish gray or olive sandy shales. 

 Toward the west as far as the Naples valley brachiopods are com- 

 mon in these West Hill flags, specially at an horizon lying 100 to 150 

 feet above the Grimes sandstone. 



In a small ravine 1 mile east of Hammondsport a calcareous lens 

 in this formation, 1 foot, 6 inches thick and several rods long, is 

 composed almost entirely of brachiopods, amongst which are 

 Orthis tioga, A try pa reticularis, Strop heo- 

 donta cayuta, Spirifer mesacostalis, Cyrtina 

 hamiltonensis and A m b o c o e 1 i a umbonata. It also 

 contains a few goniatites and orthoceratites. Brachiopods are 

 common at this horizon in the ravine south of the village. At 

 Naples where the formation is typically exposed on West Hill, from 

 which the name is derived, this fauna with several additional species 

 appears at various places but the specimens are very much less 

 than toward the east. Goniatites, which also occur in the Cashaqua 

 shale below, are occasionally seen but the characteristic lamelli- 

 branchs and gastropods of the Naples fauna have not been found in 

 this section at so high a horizon. In the Genesee river section and 

 farther west the fossils of this horizon arc exclusively of the Naples 

 fauna, no brachiopods being known therefrom. In the Watkins and 

 Elmira quadrangles both shales and sandstones are usually barren 



