144: W. H. Twenhofel — Silurian Section at Arisaig. 



(1855 : 315). In later papers he modified this view and 

 considered that the strata were the time equivalents of the 

 Clinton to Lower Helderberg of New York, and regarded it as 

 possible that strata lower than the Clinton might be present 

 (1868 : 573).. He further stated that the fauna was interme- 

 diate in position between that of New York and England. 



In 1859 Rev. D. Honeyman, then a minister in the town of 

 Antigonish, published a short paper in the Transactions of the 

 short-lived Literary and Scientific Society of Halifax giving 

 a popular description of the section. Being favorably situated, 

 he spent much time studying the rocks of this and neighboring 

 regions and appears to have made a large collection of fossils 

 from the Arisaig exposures. The results of these and later 

 studies appeared in a number of papers extending from 1859 

 to 1887 (See list at end of this article). Basing his conclusions 

 on Salter's identification of fossils, he at first considered the 

 section as extending from the Mayhill sandstone to the Upper 

 Ludlow, both of Silurian age ; but his later papers express the 

 view that the section begins in the Ordovician, the TJtica and 

 Hudson River being represented (1886 a : 318), which view 

 was supported by Hall. He made five subdivisions of the sec- 

 tion, which he called, beginning at the base, A, B, B', C, and 

 D. The most valuable of his papers are those of the years 

 1864 and 1875. Honeyman deserves a great deal of credit for 

 his earlier work, his sole stimulus being the love that he had 

 for the science of Geology. 



The most complete detailed description of the Arisaig strata 

 occurs in the Report of the Canadian Geological Survey for 

 the year 1886. Messrs. Hugh Fletcher and E. R. Faribault 

 of the Survey made the section, which from a structural and 

 penological standpoint leaves little to be desired, but in failing 

 to cite the fossils collected their work does not give the strati- 

 grapher the needed information to determine the historical 

 record of the rocks described by them. The authors assign 

 the strata to the Silurian, ranging from the Medina to the 

 Lower Helderberg. 



The latest work is by Dr. H. M. Ami, who gives a provisional 

 list of fossils, but without locating them in the section. In his 

 last published statements (1901 : 203 ; 1901 b : 354) with refer- 

 ence to the section, he applies, beginning at the base, the 

 names Arisaig, McAdam, Moydart, and Stonehouse to form 

 divisions of the series ; without, however, fixing precise limits 

 to his divisions. 



Location and Boundaries. — The Silurian rocks under dis- 

 cussion lie upon the Straits of Northumberland, at the little 

 village of Arisaig, Nova Scotia. They underlie an area about 

 six miles long by one and one-half miles wide (1886 : 41P), 



