91 



older than the Potsdam sandstone, and was thus precisely equivalent to the 

 Taconic proposed by Emmons ten years previously. It was employed in the 

 sam^ sense till 1855. 



Murray employs the Terms " LaurenUan'' and " SuronianJ^ — The Canadian 

 report published in 1857 comprised the annual reports for 1853, 1854, 1855 

 and 1856. In Murray's reports for 1853 and 1854 he describes the country 

 between Georgian bay and Ottawa river. In his report for 1855 he says : 



"Among the bowlders on Lake Nipissing many were observed to be of a slate 

 conglomerate, and they were frequently of very great size. In their aspect and gen- 

 eral character these have a very strong resemblance to the slate conglomerates of the 

 Huronian series,* from which, in all probability, they were derived " (p. 125). 



In the report for 1855, speaking of the drift in the peninsula between 

 Lakes Huron and Erie, he says : 



" The pebbles and bowlders of metamorphic rocks which abound in the gravel and 

 clay deposits, and are numerously scattered over the surface, are clearly derived from 

 the Laurentian and Huronian formations on the north shore of Lake Huron " (p. 134). 



In this passage Laurentian and Huronian are used in coordinate senses. 

 As the former had been employed in a systemic sense, it is not likely to have 

 been employed here in a geographic sense. In such case " Huronian " was 

 not employed simply in a geographic sense. Murray was undoubtedly the 

 first to employ the term "Huronian" in any sense; but as he has not ex- 

 pressed any intention to use it in a systemic sense, it would be straining a 

 courtesy to base credit for such employment on the inference above indi- 

 cated. It seems probable, nevertheless, that Murray was meditating such 

 use of the term. 



In his report for 1856, however, dated March 1, 1857, Murray, speaking of 

 the " distribution of rock formations " between Lake Nipissing and Lake 

 Huron, says : 



"The rocks of the region explored during the season embrace two of the oldest 

 recognized geologic formations, the Laurentian and Huroiiian. * -x- * The slates, 

 conglomerates, limestones, quartzite and greenstone of the Huronian occupy the north- 

 ern and western parts." "The immediate contact was nowhere distinctly seen " 

 (pp. 168, 171). 



It is thus placed beyond question that Murray was the first to use the 

 term " Huronian " in a taxonomic sense. It follows from his introduction 

 of this term that he was the first to employ the term " Laurentian " in a new 

 and restricted sense. This was in 1855 and 1856, but his reports were not 

 published till 1857. 



Murray on the Constitution of the Huronian. — In the report last mentioned 

 Mr. Murray gives a tentative statement (pp. 172, 173) of the constitution of 



♦This term appears to be employed here only in a geographical sense. IVIr. Murray does not 

 intimate that he intends it as the name of a geological system. Moreover, the rocks referred to 

 were at this time embraced in a series known as "Laurentian." 



