44 
Comparison of faunas in Trenton and Black River 
Leray 
Rock- 
land 
Cephalopoda 
Actinoceras bigsbyi Bronn 
Barrandeoceras cf, vagrans (Billings) 
Cyrioceras sp 
Oncoceras huronensis Billings 
0. sp 
Orthoceras amplicameratum Hall 
O.junceum Hall 
O. multicameratum Emmons 
0. cf. tenuistriatum Hall 
0. sp 
c 
r 
r 
r 
r 
r 
r 
r 
r 
r 
Trilobita 
Bathyurus spiniger (Hall) 
Bumastus indeterminatus (Walcott) 
B. milleri (Billings) 
B. trentonensis Emmons 
B. sp 
Calymene senaria Conrad 
Ceraurus dentatus Raymond and Barton 
cf. C. dentatus Raymond and Barton 
C. pleurexanthemus Green 
C. sp. (hypostoma) 
C. sp 
C. sp 
Encrinurus cybeleformis Raymond 
E. cf. cybeleformis Raymond 
E. cf. trentonensis Walcott 
Illaenus angusticollis Billings 
/. sp 
Isotelus gigas Dekay 
I. sp 
Pterygometopus sp 
Ostracoda 
Aparchites concinnus (Jones) 
Leperditia jabulites (Conrad) 
L. trentonensis n. sp 
L. sp 
L. sp 
Macrocypris ? siliqua (Jones) 
r 
cc 
r 
r 
r 
r 
c 
r 
r 
r 
r 
r 
r 
r 
r 
c 
r 
r 
r 
r 
r 
r 
In this table the comparison has been made of species in 
the lower Trenton and the upper Black River beds only, taking 
as a centre the transition zone mentioned above and including 
below, those beds which contain a strictly Black River-Leray 
fauna, and above, those beds which contain a strictly Trenton 
