$46 NEW YORK STATE MUSEUM 



pally distributed through the Stones river and Black river groups. 

 The single species of M a c r o n o t e 1 1 a , made known by Ul- 

 rich (49:648), comes from the Stones river group (Lowville lime- 

 stone). All the other fossils fo'und belong either to species which 

 lived throughout the Trenton age or to new species too different 

 from those known to allow taxonomic conclusions. 



It is obvious that the faunas of both the pebbles and of the 

 matrix point to a low horizon in the Trenton stage which may 

 even descend into the Black river stage. A threefold interest 

 attaches, therefore, to this fauna, firstly that of its location in the 

 eastern region, secondly that of the remarkable character of its 

 components and finally, its intercalation in the Normans kill 

 shales. 



CONGLOMERATE BED ON RYSEDORPH HILL 



This interest is hightened by the occurrence of another con- 

 glomerate bed on the top of Bysedorph hill or the Pinnacle, east 

 of Rensselaer (station S6 on map), which contains the same groupe 

 of Trenton pebbles bearing the same faunas, augmented, however, 

 b}^ numerous other species, in part new.^ The peculiar antique 

 character of this Trenton fauna of Rysedorph hill finds its most 

 pregnant expression in the numerous specimens of A m p y x 

 h a s t a t u s sp. n. (see pi. 1, fig. 1) and Remiopleurides 

 linguatus sp. n. found in the same pebbles with 

 Ceraurus and Pterygometopufi. As before ob- 

 served. Ami found similar antique forms in the Dicellograptus 

 zone of the Quebec massive. The different composition of this 

 eastern Trenton fauna when compared with the other Trenton 

 faunas of the state, is a fitting corollary to the restriction of the 

 Normans kill fauna, with which it is homotaxial, to the eastern 

 margin of the state. Both faunae, together with Ami's inter- 

 esting discoveries, point to conditions and connections of this 

 eastern border sea altogether different from those of the regions 

 to the west. 



^This is the locality termed by Emmons (Am. geol. pt 2, p. 72) and 

 Walcott " Cantonment hill." 



