144 
UTICA GROUP. 
Collingwood.—This formation is not present at Mont- 
real; but at Ottawa and in southern Ontario the Trenton 
is succeeded by a thin formation, 25 to 50 feet (7.6 to 15-2 
m) thick, characterized by the asaphoid trilobite, Ogygites 
canadensis, and several other fossils of a type more common 
in Europe than America. Among them may be mentioned 
the plicated Triplecia, Oxyplecia calhount, and Schizambon 
canadensis. Dalmanella emacerata, Leptobolus insignis, 
Zygospira modesta, Triarthrus becki and Ogygites canadensis 
are the more common fossils, the last being the 
most common of all. In lithology, the Collingwood 
represents a sort of transition between the Trenton and the 
Utica, as it consists of alternate beds of limestone and 
shale, each a foot or so in thickness. 
Utica.—Above the Collingwood at Ottawa and the 
Trenton at Montreal, are 200 to 300 feet (60-9 to 91-4 m.) 
of thin-bedded, fine-grained, brown and black carbonaceous 
shale with a small fauna, mostly graptolites. Climaco- 
graptus typicalis, Climacograptus bicornis, D1iplograptus 
pristis, Leptobolus insignis and Triarthrus becki are common 
forms everywhere, and near Ottawa Triarthrus spinosus 
and Triarthrus glaber are also found. 
LORRAINE GROUP. 
Lorraine.—The Lorraine and Richmond have not yet 
been studied in any great detail in this area, but the recent 
work of Dr. A. F. Foerste shows that both groups may be 
subdivided. In the case of both, exposures are few, as 
the formations occur in a very flat country, at a distance 
from rivers. 
The Lorraine has been explored to some extent east 
of Ottawa. It consists of sandstone and shale in thin layers, 
and contains numerous, thin, calcareous bands. The 
common and characteristic fossils are Catazyga erratica, 
Byssonychia radiata, Pterinea demissa, Cyrtolites ornatus, 
and IJsotelus maximus. 
RICHMOND GROUP. 
At some distance east of Ottawa there are exposures of 
shales and sandstone containing a large Richmond fauna, 
the most common and prominent species being the well 
known Catazyga head. 
