12 NEW YORK STATE MUSEUM 



FEET 



1 2 Calcareous shales full of graptolites 50 



[3 Sandy reddish shales breaking up into square-faced pieces 10 



Below these fossiliferous limestones there are 600 to 800 feet of massive lime- 

 stones and marble with Orthoceras. These include the Chazy (with Maclurea 

 magna) and Trenton. The graptolite beds are, as the section shows, at the top of 

 the series, not far below chert beds with Subcarboniferous fossils. 



The fauna consists of the following species : 

 Nemagraptus gracilis var. surcularis Hall (r) Diplograptus foliaceus var. alabamensis 

 Dicellograptus smithi nov. (cc) nov. (cc) 



D. moffatensis Carruthers var. alabamensis Climacograptus cf. putillus [Hall) (c) 



nov. (cc) Cryptograptus tricornis {Carruthers) (c) 



D. cf. mensurans nov. (rr) Glossograptus ciliatus Emmons (c) 



While the essential identity of this fauna with our Normanskill grapto- 

 lite fauna can not be gainsaid, this identity can not be taken as demonstrat- 

 ing more than the general fact of the Trenton age of the Normanskill 

 fauna, because, on one hand, the Alabama fauna contains enough differing 

 elements to be not exactly identical and on the other hand it is open to 

 question whether this upper Trenton of Alabama is exactly equivalent to 

 ours. 



Hence while the Trenton age of the Normanskill zone can be consid- 

 ered as well established, its exact place in the Trenton formation is still 

 open to question. On the other hand, the position of the Normanskill 

 fauna in New Jersey and Alabama excludes also the possibility that that 

 fauna can be of greater than Trenton age ; hence it can not be placed 

 between the Chazy and Trenton limestone as Lapworth provisionally 

 assigned it. The fact that still another well differentiated zone [see posted 

 p.29] intervenes between those of the Normanskill and Utica shales and 

 the marked difference of the Normanskill and Utica faunas argue strongly 

 however for the position of the Normanskill shale below the upper Trenton. 



Since the original discovery of the zone at the Normanskill, numerous 

 other localities, to be noted further on, have become known in the slate 

 belt of eastern New York on both sides of the Hudson river. Walcott, in 

 his investigation of the slate belt [1888] discovered many localities, espc- 



