178 THE CANADIAN NATURALIST. [Vol. X. 



by him stited to be highly charncteristic of the Huronian series, 

 and his description seems to me to be so exactly applic.ible to 

 the present c.ise, that I shall take the liberty of quoting it, 

 together with a summary of his inferences and conclusions; al- 

 though my own deductions may be somewhat at variance with 

 his as to their relations with tlie surrounding rocks. 



In the above-mentioned Keport, page 192, Dr. Hunt says: 



" Felsites and felsite-porphyries are well-known in eastern Massa- 

 chusetts, and may be traced from Macchias and Eastport in Maine 

 along the southern coast of New Brunswick to the head of the Bay 

 of Fundy, with great uniformity of type, although in every place sub- 

 ject to considerable variations, from a compact jasper-like rock to 

 more or less coarsely granular varieties, all of which are often porphy- 

 ritic from feldspar crystals, and sometimes include grains and crystals 

 of quartz. The colors of these rocks are generally some shade of red 

 varying from flesh-red to purple ; pale-yellow, gray, greenish and even 

 black varieties are, however, occasionally met with. These rocks are 

 throughout this region distinctly stratified, and are closely associated 

 with dioritic, chloritic and epidotic strata. They apparently belong, 

 like these, to the great Huronian series." 



Again, speaking of the same rocks, at page 198, he says: 



" These were compared with the similar strata along the Atlantic 

 coast, from Rhode Island to New Brunswick, interstratified with rocks 

 having the characters of the Huronian series, to which great division 

 I have provisionally referred these bedded petro-silex rocks, with the 

 suggestion that they probably occupy a position near the base of the 

 series. These rocks were declared to be identical in lithological 

 characters with the Halleflinta, or stratified flint-rock of the Swedish 

 geologists, which is by them assigned to a horizon just above the 

 more ancient or Primitive Gneiss ; and are important, as including in 

 Norway, the most considerable deposits of crystalline iron ores. These 

 same rocks are met with in various localities in the Huronian series, 

 on the Upper Lakes, and are well displayed, as observed by the writer, 

 in a small island lying a little to the south of St. Ignace Island, and 

 for some distance along the shore to the adjacent mainland to the 

 southwest. E])idote, chlorite and a steatitic mineral are occasionally 

 met with in these petro-silex rocks, and magnetic and specular oxyds 

 of iron occur disseminated, in interstratified masses and in veins inter- 

 secting the strata." 



Again, at pages 229 and 232, he says: 



" The reader is now prepared to understand the significance of the 

 question raised by the writer in 1871, as to the existence of the felsite 

 or petro-silex porphyries in place in the Lake Superior region ; since 

 these rocks, which had then been found by him to belong to the 



