52 



NEW YORK STATE MUSEUM 



The following are the more common species: 



Lyriopecten tricostatus Vanuxem 



Grammysia sp. 



Spirifer mesastrialis Hall 



Sp. mesacostalis Hall 



Atrypa reticularis Linne 



Productella lachrymosa Hall 



P. speciosa Hall 



P. boydi Hall 



Orthis tioga Hall 



O. carinata Hall 



Schizophoria impressa Hall 

 Stropheodonta cayuta Hall 

 Leptostrophia perplana Conrad var. 



nervosa Hall 

 Orthothetes chemungensis Conrad 

 Tropidoleptus carinatus Conrad 

 Liorhynchus mesacostale Hall 

 Chonetes scitulus Hall 

 Lingula cf. melie 



Prattsburg shales and flags 



Above the High Point sandstones there is a partial return to 

 argillaceous conditions and for about 250 feet the beds are mostly 

 shales or thin, uneven, blocky or shaly sandstones. A few of the 

 sandy layers are compact and hard and others are schistose or 

 straticulate. 



In the Genesee river section at Wiscoy and vicinity these beds 

 are soft, shaly and somewhat calcareous and contain only Portage 

 fossils but eastward from that point they are harder and in the 

 town of Prattsburg and on these quadrangles they contain many 

 Chemung and very few Portage fossils. Toward the southeast 

 they become softer again and at Elmira there is an approach to the 

 conditions at Wiscoy. 



Although this formation is the surface rock over large areas on 

 these quadrangles, outcrops that show more than a very few feet 

 of the strata are rare owing to its elevation above the more deeply 

 excavated parts of the ravines, except near the southern border 

 where the drift mantle is quite heavy. 



It is partly exposed in the ravine 1 mile east of Savona and in 

 another 2^ miles south of that Village, also in a ravine and along the 

 roadside 2 miles north of Sonora. 



The more common fossils of the Prattsburg shales and sand- 

 stones are: 



Paleoneilo rilosa (Conrad) Hall 

 P. constrict a (Conrad) Hall 

 Lyriopecten tricostatus Vanuxem 

 Pterinopecten imbecilis Hall 

 Macrodon chemungensis Hall 

 Mytilarca carinata Hall 

 Grammysia circularis Hall 

 Leptodesma potens Hall 

 L. maclurii Hall 



L. spinigerum Conrad 

 L. robustum Hall 

 L. interplicatum 

 Spirifer mesastrialis Hall 

 S. mesacostalis Hall 

 Productella lachrymosa Conrad 

 P. hirsuta Hall 

 P. speciosa Hall 

 Liorhynchus mesacostale Hall 



