TRENTON CONGLOMERATE OF RTSEDORPH HILL 89 



probable, that the long, leaf-shaped plate figured by the writer 

 represents this plate of the exoskeleton of Lepidocoleus 

 j a me si, and that the apparent carina is the reverse side of 

 that groove. Several specimens of this type of plate structure 

 have been observed by the writer. 



Dr Woodward has described^ a species of TurrilepaS, obtained 

 by Dr Ami in the lower TJtica beds of Ottawa, as T u r - 

 rilepas canadensis. This species is quite certainly not 

 identical with the one represented by the Trenton and Utica 

 specimens of the vicinity of Albany, referred to Lepidoco- 

 leus jamesi, for its plates are about three times as large 

 as those of the latter, and differ materially in shape; the carina 

 also lies not medially but close to the longer side. (Group 5) 



ANALYSIS OF THE FAUNA OF THE CONGLOMERATE 



Fossils contained in the various kinds of pebbles 

 c=common; cc=Yery common; r=rare; rr=very rare 



GROUP 



1 Gray limestone 



Hyolithellus micans Billings 



2 Gray and reddish sandstone 



None 



3 Black crystalline limestone (Chazy limestone) 



Bolboporites americanus Billings 

 Palaeocystites tenuiradiatus Hall sp. 



4 Lowville limestone 



Tetradium cellulosum Hall sp. 



5 Black compact limestone 



Streptelasma corniculum Hall c 



Diplograptus foliaceus Murch. sp. r 



Climacograptus scharenbergi Lapicorth r 



Stomatoi>ora inflata Hall sp. c 



Stictopora cf. elegantula Hall r 



Callopora multitabulata TJlrich cc 



Sipbonotreta ininnesotensis Hall & Clarke rr 



Crania ti*entonensis Hall r 



Rafinesquina alternata Emmons sp. c 



Leptaena rbomboidalis Wilckens c 



Plectambouites sericeus Soicerly sp. c 



P. pisum sp. nov. cc 



Geol. mag. 3d ser. 1889. 26:274. 



