316 THE CANADIAN NATURALIST. [Yol. vi. 



what specimens he could send in exchange. After mentioning 

 several species, he says : 



'^ I can spare a good specimen of what Prof. Hall describes 

 as Olenus asaphoides, which I got from the upturned slates of 

 Vermont, twenty-five miles north of Burlington and four miles 

 from Lake Champlain. Emmons declares it below the New 

 York system. It is singular that no other fossils of any kind are 

 found in the locality which has furnished several of this tri- 

 lobite," 



Shortly afterwards the trilobite was received by me at Mont- 

 real, and I was much surprised to find it a true primordial form, 

 but not an Ohnus. It seemed to me to be more nearly allied to 

 Paradoxides and it appears also that I communicated this 

 opinion to Col. Jewett, for I have a letter from him dated 11th 

 of May, 1859, in which he says : 



" Should you have any doubts of the trilobite sent you being 

 a true Paradoxides^ I will send you others which display more 

 graphically the characters." 



After studying the fossil for several days, I showed it to the 

 officers of our Survey, and pointed out that its primordial aspect, 

 iudic ited a horizon far below the Hudson Kiver group, and per- 

 haps even below the Potsdam sandstone. The subject was 

 much discussed, and Sir W. E. Logan proceeded, soon after- 

 wards, to examine the geological structure of the region in 

 which the trilobite had been found. Thus the re-investigation 

 of the Taconic question was commenced by the Canadian Survey 

 in the spring of 1859. [ consider this a very important step, 

 because, for many years, the views of Dr. Emmons had been 

 regarded as constituting a theory so utterly baseless, that none of 

 the leading geologists could be brought to think it worth a single 

 day's work in the field. Sir W. E. Logan, however, was not of 

 that opinion, and after seeing the trilobite, took to the field at 

 once. Although he did not, at first, find any good reason to 

 depart from what had been considered, for more than twenty 

 years, the true arrangement of the rocks in question, yet he con- 

 tinued the investigation, whenever his other duties would per- 

 mit, until his final decision was given, on the last day of Decem- 

 ber, 1860, just twenty months after the trilobite was received by 

 me. 



