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many species are common to both. The fossils which are 

 especially characteristic are Monograptus cf. riccartoensis. 

 Dalmanella elegantida, Leptaena rhomhoidalis , Camar- 

 otoechia neglecta, A try pa reticularis, Spirifer crispus, 

 Bucanella trilohata and Calyniene tuber culata. The Mc- 

 Adam formation has a thickness of 1120 feet (366 m.). 



Zone I. — The iron ore zone. Williams has described 

 this zone as consisting of " firm shales and thin-bedded 

 sandstones with 2 feet 3 inches of ferruginous shale and 

 weathered hematite." The hematite is a "fossil ore" sim- 

 ilar to the Clinton ore of the Appalachian region. The 

 fossils are Dalmanella elegantula, Leptaena rhomhoidalis, 

 Camarotoechia near neglecta, Homeospira sp., Meristina 

 near oblata, and Cornulites flexuosus or proprius. Since 

 the fauna does not contain Monograptus clintonensis or 

 Anoplotheca hemispherica and is more closely related to 

 that which follows than that which precedes it has been 

 referred to the McAdam formation. The thickness has 

 been estimated by Williams at 100 feet (30 m.). 



Zone 2. — Grey and greenish impure limestones inter- 

 stratified with shale of the same color. The zone ends at 

 the mouth of McAdam's brook. The identified fossils 

 are: — Pholidops implicata, Dalmanalla elegantula, D. (a very 

 large new species) , Leptaena rhomhoidalis, Camarotoechia 

 neglecta, C. cf. ohtusiplicata, Atypra reticidaris, Pterinea 

 emacerata, Tentacidites sp. and Homalonotus daivsoni. 

 The thickness is 540 feet (165 m.). 



Zone 3.. — Dark grey to black carbonaceous shale, the 

 greater portion with papery bedding cleavage. At several 

 levels are lenticular beds of fine-grained cross-laminated 

 sandstone. The fossils are: — 



Dalmanella elegantula 



Laptaena rhomboidalis 



Chonetes tenuistriatus 



Camarotoechia neglecta 



C. obtusiplicata 



Atrypa reticularis 



Spirifer crispus 



Grammysia sp. - 



Cleidophorus sp. 



Bucaniella trilobata 



Calymene tuberculata. 

 About 75 feet (22 m.) from the top is a layer about one 

 inch thick in which Monograptus cf. riccartoensis is present 



