TRENTON CONGLOMERATE OF RYSEDORPH HILL 95 



the Lorraine, Rafinesquina alternata in Canada from 

 the Chazy into the Lorraine, Platystrophia biforata 

 from the Chazy in Canada to the upper Siluric in the west. 



These, as well as the new forms, can therefore be excluded as 

 furnishing no data for the determination of the taxonomic posi- 

 tion of this fauna. Also Climacograptus scharen- 

 b e r g i is of no use for this purpose, as it has hitherto been 

 found only in another facies, the Quebec and Normans kill shales, 

 an^d' S t i c t o p o r a cf . e 1 e g a n t u 1 a , C r a n ia cf . t r e n - 

 tonensis, Siphonotreta cf. minnesotensis, 

 and C o n u 1 a r i a cf . t r e n t o n e n ,s i s are not positively 

 identified. Of the remaining members of the fauna, P 1 e c t a m - 

 bonites sericea, Dalmanella testudinaria, 

 Ceraurus pleurexanthemus range from the Lowville 

 limestone to the Lorraine or Richmond beds. Orthis tri- 

 c e n a r i a, L p h o s p i r a b i c i n c t a, L i o s p i r a a m e r i - 

 -c a n a , 1 1 1 a e n u s a m e r i c a n u s and P t e r y g o m e t o - 

 pus callicephalus begin in the Lowville beds and rise 

 into the Trenton. These, together with all the forms mentioned 

 below which are younger, prove the black compact limestone to 

 be younger than the Chazy, in spite of the Chazy aspect of some 

 of its trilobites. Stomatopora inflata, Callopora 

 multitabulata, Whitella> ventricosa, Proto- 

 warthia cancellata, Isotelus maxim us lived 

 either in New York, Canada or the west from the Black river 

 into the Trenton period. Streptelasma corniculum, 

 P h o 1 i d o p s t r e n t o n e n s i s , L e p t a e n a r h o m b o i- 

 d a 1 i s , C n r a d e 1 1 a c o m p r e s s a , C a r i n a r o p s i « 

 carina t a, Zitteloceras hallianum, Calymmene 

 sen aria, Bronteus lunatus and Bythocypris 

 c y 1 i n d r i c a have not yet been found below the Trenton. 

 None of the species obtained from the black compact limestone 

 is restricted to the Lowville or Black river limestone; it must, 

 therefore, be concluded, that these pebbles are of Trenton age. 

 The inquiry for the more precise location of the bed within the 

 Trenton terrane meets with the greatest difficulty from the lack 



