140 
Beauharnoits—The Beauharnois is probably a com- 
posite formation, and a great deal remains to be done on 
its stratigraphy and fauna. At the typical locality, along 
the Beauharnois canal, southwest of Montreal, it consists 
of dolomite and rather pure, blue-black limestone, with a 
fauna allied to that of the Beekmantown at Beekmantown, 
New York, and indicating a position low in the Lake 
Champlain section. Some of the typical fossils in this 
region are Hormotoma anna, Holasaphus mooret, Isoteloides 
whitfieldi, Bathyurus angelin1, Ophileta complanata, and 
several ostracods. Farther west, in the vicinity of Ottawa, 
the strata are more sandy and there is more light gray, 
rusty dolomite. The fauna here has some species like 
the eastern ones, but Protocycloceras lamarcki, Pleuroto- 
maria canadensis and other mollusca dominate the assem- 
blage. It hardly seems probable that there is anything as 
modern as the Fort Cassin fauna of the Lake Champlain 
section in the Ottawa or St. Lawrence valleys. 
CHAZY. 
Aylmer Formation.—The greater part of this formation 
consists of sandstone and shale, the beds at the base con- 
taining in places very coarse material, as in the vicinity 
of Grenville, Quebec, and Hawkesbury, Ontario, where the 
contact between the Aylmer and Beauharnois is well 
shown. The sandstone is not well exposed around Mont- 
real, but may be seen at a number of places in the immediate 
vicinity of Ottawa. The sandstone has a considerable 
fauna, a part of which is known only from the Ottawa 
valley, but there are a few species which are common to 
this sandstone and the Upper Chazy limestone of the 
Champlain valley, and still more which range throughout 
the sandstone and limestone of the Aylmer formation. 
The limestone in the upper part of the formation is well 
developed at Montreal, but thins westward, so that at 
Ottawa the calcareous member of the formation is very 
unimportant. In the vicinity of Montreal and as far west 
as Hawkesbury, the limestone is hard, fairly pure, thick- 
bedded, and frequently a solid mass of such Upper Chazy 
fossils as Camarotechia plena, Camarotechia orientalis, 
Malocystites murchisoni, Sigmacystis barrandet, Sigmacystis 
emmonst, Bolboporites americanus, etc. About Montreal 
this limestone is extensively quarried at St. Martin Junc- 
