5^ 



Atey. 



Hall. 7^. 



( Terebratula aMnis^ M. C. ; lerebraUda prisca^ Yon Buch. ; 



Vlfl Terebratula reti cul avis ^ 



. . ^^^^^^^ Brown, Leth. Geog.; Airy- 



pa aiRniss Sil. Res. ; Hall, 

 page 198, fig. 79, 4.— VI lie. 

 Hamilton formation. Hall 

 gives it as Atrypa prisca ; 

 size variable; often flat- 

 tened: abundant; also in 

 Ylllg. 



{Atrypa aMnis^ Atrypa lentiformis.) Hall, page 215, fig. 



Vanux- 

 u ra, p. 

 163, fig. 



Hall, page 163, fig. 41, 3 ; page 215, 

 95, 3. VIII d, Tully limestone. 

 The edges of the valves are much 

 compressed, and look as if they 

 J, «^ — .-■.„ ■ — .::::^ wero friugcd. 



{Atrypa trihulis,) Hall, page 271, fig. 124, 3, 3<^, 3&. VIII g. 



w.ji Chemung for- 



*c5L,<g^8^^ mation. Clay- 



pole (Report on 

 Perry Co., Fa. 

 F 2, preface, 

 lists o f fossils) 

 records Atrypa 

 reticularis 

 from F/, Lower 

 Helderberg formation ; Vlllh, Marcel- 

 lus formation ; VIII c^ Hamilton forma- 

 tion; and VIII g^ Chemung formation. 

 It is one of the commonest forms in the 

 rocks in all the counties of Middle 

 Fennsylvania. In Monroe county, at 

 Stroudsburg and elsewhere along the 

 Corniferous limestone outcrop ; at Mar- 

 J^4-. shall falls, in the base of it (White, G6, 



H.IU 



