Raymond : The Cha;^y Formation and its Fauna. 585 



parts of the Chazy are referred to the Birdseye limestone. The following 



fossils are listed from Vermont localities : 



Phylopsis tuhitlositm, Macliirea 7itagna, 



Rhyufhonella aldlis, Cyitoceras, 



Rhyiichouella plena, Bmanio, 



Cluctetes, Jllamts crassicatida, 



Calymetie mttlticosta, Illanits. 



The thickness is estimated at 300 feet. 



" The Chazy covers more surface in Vermont than any other of the Lower 

 .■^ilurian limestones, and it seems to be one of the thickest." 



The range of the Chazy formation in the slate is given as follows : 



" It is not found south of Benson, and appears next at Larrabee's Point, 

 being very thin at both places. Curving at Larrabee's Point, it crosses into 

 New York, where it appears at Crown Point, but crosses back to Vermont at 

 Chimney Point. An anticlinal commences here, extending through the 

 western part of Addison County to Charlotte, then the formation goes under 

 the lake to Valcour Island and South Hero. In Vermont the most northern 

 exposure is at Isle La Molte." 



1863. Bii.Li.NGS, E. On the Parallelism of the Quebec Group with the Llandeilo of 

 England and Australia, and with the Chazy and Calciferous Formations. 

 Canadian Naturalist and Geologist, Vol. 8, pp. 19-35. 



In this paper Mr. Billings discusses the position of the Quebec group and 

 places it as equivalent to the upper part of the Calciferous and all of the 

 Chazy. The following (juotations are of interest : 



" In 1859 I made an examination of all the Calciferous and Chazy fossils, 

 in the Provincial Museum, and found that there were 41 species of the 

 former and 129 of the latter, but not one species was clearly identified as 

 common to the two formations." ..." I think it probable that a large 

 portion of the Quebec group is of an age between the Calciferous and 

 Chazy. But I do not believe that this would be sufficient to account for so 

 great a number of species distinct from those of these two formations. The 

 existence of zoological provinces in the Silurian seas, although not clearly 

 ])roved, is something that should always be kept in mind. . . . There 

 is here another break (between the Chazy and Black River), but not so 

 decided as between the Calciferous and Chazy." 



1863. Logan, Sir Wili.i.am E. Geology of Canada, pp. 123-135. 



In the chapter on the Chazy formation in Canada Sir William Logan 

 gives in detail its distribution and characters in the region about Montreal 

 and in the Ottawa Valley. The thickness of the formation is given at 

 about 300 feet. It is noted that from St. Lin and Industry to the Mingan 

 Islands, a distance of five hundred miles, the Chazy is not exposed. 



On pp. 294-296 the conditions of deposition are discussed. The author 

 suggests that the Cambrian and Ordovician were laid down in a sea which 

 had a steeply sloping coast, but with a shelf near shore. The Potsdam 

 sandstone was a littoral deposit on the shelf, while the Georgian was de- 



