334 A. Winchell on Drift Materials in Michigan. 
not to speak of their lithological characters, convince us that the 
rock belongs to a much earlier epoch. 
In short, no doubt could be entertained by one who has ex- 
amined the subject, that these fragments appertain to the age of 
the Corniferous limestone. The rock, in structure, is irregular, 
often brecciated, with streaks and nests of bituminous an 
gillaceous matter. At other times it is compact and massive. 
Not unfrequently it presents the peculiar structure known as 
“‘Jignilites.” All these characters belong to the Corniferous 
limestone as exposed along the western shore of Lake Erie, and , 
at numerous points throughout the county of Monroe. # 
Turning to the more reliable evidence of the fossil remains, 
it may be stated that the following are examples of the more 
frequent identifications : i 
At 92, Heliophyllum Canadense Billings, Clisiophyllum Onei- 
daénse Bill., Acervularia Davidsoni E. & H., Conocardium tragona 
all, Proetus crassimarginatus Hall, Amplecus and Favosites. : 
At 182, Lucina proavia Goldf., Conocardium trigonale, Den- 
talium and Fenestella. 
t 208, Lucina proavia and three species of Bryozoa. 
At 230, Slrophomena rhomboidalis Wahl, Chonetes glabra Hall, 
Spirifera gregaria Clapp, Atrypa reticularis Dal. : 
At 238, Chonetes hemispherica Hall, Atrypa reticularis, Cyrto- 
donia (Vanuxemia) Tompkinsi Bill, Pleurolomaria rotunda, Hall. 
: ; 
0, Chonetes lineata Hall, Atrypa reticularis. : : 
At 289, Chonetes lineata, C. glabra Hall, Atrypa reticularis, 
Leiorhynchus multicosta Hall, Rhynchonella Thalia Bill., Lueina 
_ proavia, Proetus crassimarginatas Hall, Platyceras and Proetus 
is Vanux é 
Spirifera varicosa Hall, 8. gregaria, Atrypa reticularis, Charionella 
scitula Bill., Rhynchonella Thalia, Lucina proavia, Conocardium 
trigonale, Proetus crassimarginatus, Fenestella, Producta (two spe 
cies), Streplorhynchus, Athyris, Platyceras. 
At 292, is Vanuxemi, O. propingua Hall. 
t 296, Chonetes glabra, C. arcuata Hall, Stricklandia elongata 
Bill. 
A 38, Stroph: hemi: heri i 
| The chee emispherica. 
