Huntingdon Counties, Central Pennsylvania. 533 



Tuscarora Thick-bedded white quartzite. Arthrophycus 



quartzite alleghenyensis, (harlani), in upper part. Exten- 

 sively used for silica brick. Called ganister. 



Juniata Red lumpy shale or mudrock, red and greenish 



formation gray sandstone. Some finely cross laminated. 

 No fossils. 



Oswego Medium thick-bedded gray sandstone. Some 



sandstone finely cross laminated. No fossils. Bald Eagle 

 sandstone of Grabau. Oneida conglomerate of 

 Pennsylvania Second Geological Survey. 



III. 



Reedsville Thick, dark, rusty weathering, sandstone at top 



shale with Orthorhyncida linneyi, ByssonicMa radiata 



and others. Maysville age. Persistent to Ten- 

 nessee. Shale with thin limestone layers in 

 upper half. Fissile (shoe peg) shale in lower 

 half. Calymene senaria, Dalmanella multisecta, 

 Rafinesquina. Black shale at bottom with grap- 

 tolites. Eden age. 



Trenton Thin-bedded black limestone weathering with a 



limestone gray film on surface. Sparsely fossiliferous. 

 Cryptolithus tessellatus = Trinucleus concen- 

 tricus, Plectambonites sericea. 



Rodman Dark crystalline limestone weathering with a 



limestone rough granulated surface; very characteristic 

 and persistent. Fossiliferous. Echinosphaerites 

 zone at top. Upper Black River. 



Lowville Dark, thick-bedded, pure limestone, glassy to 



limestone fine-grained. Extensively quarried for flux. 



Streptelasma profundum, Tetradium cellulosum, 



Beatrecia gracilis, Lichenaria typa f. Lower 



Black River. 



Carlim Dark, fine-grained limestone, extensively quar- 



limestone ried for flux. Fossils scarce except in Lemont 

 argillaceous limestone member. Leperditia fdb- 

 ulites, Isochilina amiana, Leptaena incrassata in 

 bottom. Tetradium syringoporoides through- 

 out; Lemont member impure, not quarried. 

 Hebertella vulgaris, Rafinesquina champlainen- 

 sis, Protorhynca ridleyana f, Maclurites magna. 



Bellefonte Thick-bedded dolomite yielding much dense 



dolomite chert. Fossils scarce. 



