20 NEW YORK STATE MUSEUM 



Dicellograptus fauna. Of the Alabama graptolites \_scc list on p. 12] 

 Neraagraptus gracilis var. surcularis, Dicellograptus 

 cf. mensurans, Cryptograptus tricornis and Glossograp- 

 tus ciliatus are forms occurring in our Normanskill shale; Crypto- 

 graptus tricornis also entering into the next zone. Dicello- 

 graptus smithi is a close relative of D. sextans, another 

 Normanskill form, indicating a transition of that species to Dicranograptus. 

 Likewise Dicellograptus moffatensis var. alabamensis and 

 D. foliaceus var. alabamensis are provincial representatives of 

 species occurring in this horizon but also found in later beds; the former is 

 thus far known only from Great Britain, where it ranges from the Llanvirn 

 to the Hartfell beds, the other is a cosmopolitan form. A small Clima- 

 cograptus which is nearest related to C . p u t i 1 1 u s may indicate syn- 

 chrony with one of the later subzones of the Dicellograptus beds, and the 

 large percentage of forms closely related to, but still distinct from Normans- 

 kill species, is probably best explained as due to geographical or provincial 

 separation. 



Following the slate belt northward into and through Vermont, no out- 

 crops of the Normanskill shales have as yet been found in that State, but 

 the presence of the zone with identical faunas in Canada for a long distance 

 along the St Lawrence, made known by Lapworth [1887, Griffin Cove, 

 Marsouin river, Little Mechin river, Cape Rouge, Quebec, Fox and 

 Magdalene rivers] and Ami j 1889, Island of Orleans, Etchemin river, 

 Quebec, and Montmorency river, Quebec, etc.] leave little doubt of the 

 continuation of the zone through Vermont ; and also the occurrence of an 

 outcrop of the next graptolite zone near Lake Memphremagog, close to the 

 Vermont and Canada boundary line points to the same inference. 



The apparent absence of the Normanskill shale from Vermont is epiite 

 obviously duv. to the stronger folding of the slate belt, possibly under the 

 influence of the Adirondack massive in the west. This funis its expression 

 in the greater vertical hiodit of the resulting 1 mountain chains (Green 

 mountains) and has led to a narrowing of the belts of shales and their 



