104 Canadian Record of Science. 



soapstone, magnetic iron, chromic iron, mica and enstatite. 

 The first mentioned occurs abundantly in veins and bedded 

 masses ; whilst magnetite, as already stated, is found dis- 

 seminated through the serpentine, and forming veins in the 

 asbestus ; chromite is much less frequently met with, 

 although the asbestus miners persist in calling all the iron 

 found in their workings, chromic. Small particles of mica 

 are found in the serpentine at various points. It is fairly 

 abundant at Coleraine, and in G-arthby township : it occurs 

 in curious association with picrolite, plates of mica being 

 arranged in columns which alternate with the picrolite 

 columns. 



Enstatite, conspicuous because of its bronze lustre, is 

 found in the serpentine at the Calvin-Carter mine, Black 

 Lake. 



The Lower Helderberg Formation of St. 

 Helen's Island. 



By William Desks, B.A. 



The existence of Upper Silurian fossils on St. Helen's 

 Island was first discovered in the autumn of 1856 by Sir 

 William Dawson, on the occasion of a Geological excursion 

 to the Island with his class, when Atrypa reticularis, a 

 species of Favosites, and other fossils sufficient to establish 

 the age of the limestone were obtained. These fossils were 

 handed over to Sir William Logan and more extensive 

 collections subsequently made by Mr. Billings. Reference 

 was made to these in 185*7, at the meeting of the American 

 Association, when its members visited the Island. This 

 was the first publication of the facts. 



The structure of St. Helen's Island was described in the 

 Geology of Canada (1863), and the following facts stated : — 

 " The outlier appears to repose on the Utica formation, the 

 shales of which, with some of their characteristic fossils, are 



1 Lots 5 and 6, Range I, south. 



