FORMATIONS OF ORDOVICIAN AGE. 51 
Hf we tabluate the thickness of these several Ordovician formations 
as they occur in their more typical New York and Canadian exposures, 
comparing them with the New Jersey section, some such relations 
; d 
Ney Eels New Jersey. 
Lorrain, 
600. 
ea 
i> 
— 
4 
MD 
fg 
a 
i 
[aver 
EE EE Zi 
g 
ral 
p 
‘am 
Utica, 
400. 
Black River Norman’s Kill 
TS) eat Ga ES 
Bae Fauna. 
Trenton, : 
Black River 
300. and Trenton, 
135. 
EET, 
as are exhibited in the accompanying 
table may be shown. 'The thickness 
of the New York and Canadian for- 
mations used are somewhat arbi- 
trarily chosen, but in all cases they 
have been under rather than over- 
estimated. Winchell and Ulrich* 
have used greater thicknesses for the 
same formations in a comparison 
with more western localities, the 
Trenton being estimated as 450 feet, 
the Utica 460 feet and the Lorrain 
825 feet. 
The organic remains in the Hudson 
River formation are exceedingly rare, 
only three fossil localities having been 
observed in the State. 
Locality 44 A.—This locality is in 
the flagstone quarry within the lim- 
its of the borough of Sussex. At 
this place the strata are nearly verti- 
cal in position and the fossils occur 
only in a thin bed but a few inches 
in thickness, which is exposed near 
the front of the quarry. This bed is 
a very calcareous sandstone, and is 
crowded with many specimens of a 
small variety of Plectambonites seri- 
ceus, with a few other species rarely 
represented. The fossils may be 
most easily detected in the weathered portions of the rock. The 
species which have been identified are as follows: 
1. Cornulites sp. undet. 
2. Plectambonites sericeus (Sow). 
3. Plectorthis plicatella (Hall). 
4. Dalmanella testudinaria (Dal.). 
* Geol. and Nat. Hist. Surv. Minn., vol. III., pt. IL., Paleontology, p. Ixxxix. 
