138 



at that time. The work of exploration was, however, carried out in the 

 meantime by the employment of specialists who were selected to carry 

 out special examinations of particular mineral locations, and whose 

 reports were of great value, or by what were considered as permanent 

 employees, who carried forward the work along certain regular lines 

 laid down by the director himself. The attempt to give, even in the 

 briefest form, a synopsis of the work of each of these would cause me to 

 trespass on your time to an unwarrantable extent. The particulars of 

 such work will, however, be found summarized in the preface of that 

 great volume, the "Geology of Canada," 1863, in which the leading 

 features of the operations of the Survey to that date are admirably pre" 

 sented. 



Among the important changes in nomenclature which owe their 

 origin to the labours of our Canadian geologists of this period, two, at 

 least, are of special interest. The great series of rocks which had been 

 described by leading geologists for many yeai^s under the title of Pri- 

 mary, or the Primitive group, and, for some years prior to 1854, by 

 Logan himself as the Metamorphic series, comprising all those which 

 were held to underlie the lowest fossiliferous zone, were, in the report 

 of that year, styled the Laurentian, and at the same time, in i-egard to 

 the palaeozoic formations, the nomenclature of the New York Survey, 

 by which standard these rocks had for many years been classified, was 

 changed to correspond with that employed in the English Survey, and 

 the terms, Lower and Upper Silurian and Devonian came into general 

 use. In the following year, 1855, the great group of rocks which bor- 

 der Lakes Huron and Superior, and which, in the reports of Dr. Bigsby, 

 were styled the Transition series, were grouped under the new name 

 Huronian. This term was first officially announced in a small volume 

 prepared for the Paris Exhibition of that year and styled "Esquisse 

 Creologique du Canada." The former term, Laurentian, proved so 

 happily chosen that it was subsequently adopted by the English Survey 

 and applied to the great masses of ci-ystalline gneisses and similar r'ocks 

 which occur on the west coast of Scotland and elsewhere in the British 

 Isles, thus proving in what high estimation the labors of our own 

 geologists wei^e held by the ablest workers in foreign fields. 



