THE TILESTONE FAUNA 343 



of the Lower Helclerberg. Preparatory to the international exhibition of 

 1862, Doctor Honeyman* made a collection of the Arisaig fossils for Sir 

 R. Murchison, which were submitted to J.W. Salter for identification. By 

 this means the equivalency of the Upper Arisaig fauna was established. 



Regarding this identification Honeyman writes in the paper above 

 cited : 



" Sir Roderick Murchison, at my request, very kindly asked Mr Salter to exam- 

 ine it [collection of Arisaig fossils and rocks], who accordingly inspected my 

 divisions of fossils, and, studiousty avoiding all inquiry into the opinions already 

 entertained, he unhesitatingly referred my Upper Ludlow to the Ludlow Tilestone 

 my Wenlock (?) to the Aymestry limestone, and Hall & Dawson's Clinton to a repe- 

 tition of the Ludlow Tilestone." f 



In this paper Honeyman published a list of the species of the Upper 

 Arisaig from the rocks west of Arisaig pier, near McAra's brook, con- 

 taining fifty-eight entries. In this list are found four species identical 

 with the Tilestone fauna of Murchison 's Silurian system ; two others are 

 apparently identical, but differently named, and most of the species of 

 the two faunas are very closely related representative species. 



In 1887 a report on Nova Scotian geology was published in the Annual 

 Report of the Canadian Geological Survey by Fletcher and Faribault. X 



The section of the upper 1,038 feet of the Arisaig rocks is given in 

 this report of 1887 as follows. It is compiled from the exposures along 

 the gulf shore between McAra's brook and Arisaig pier. It is E 6 of 

 their classification, and is called Lower Helderberg. It rests on E"5, 

 the Niagara. The junction of the two at Joseph McDonald's cove is 

 shown by a photograph taken by T. C. Weston (number 6, opposite 

 page 40P) : 



Section of Silurian Rocks at Arisaig in descending Order 



E 6. Lower Helderberg : 



Feet 



1. Reddish and purplish altered flags with bright emerald green blotches 



and layers ; more or less argillaceous, flinty, and splintery, containing 

 thin calcareous layers full of blackened shells. The red and purple 

 beds greatly predominate. They end about 15 yards northeast of 

 McPhersons brook. Dip, 166°<46° 100 



2. Dirty green, greenish, and gray quartz-veined flags and shales, holding 



encrinities and shells in abundance ; seen in Stonehouse brook as 

 well as on the shore. Veins cut across the bedding and are some- 

 times three inches thick ; perhaps unconformable to 1. Dip, 207°< 

 41° ; end at the mouth of Joseph McDonalds brook 310 



* On the Geology of Arisaig, Nova Scotia, by D. Honeyman, Quarterly Journal Geol. Soc., vol. 

 xx, 1864, p. 333, etc. 



f Quarterly Journal Geol. Soc, vol. xx, p. 334. 



% Rept. Geol. Survey and Expl. in counties of Guysborough, Autigonish, Pictou, Colchester, and 

 Halifax, Nova Scotia, from 1382 to 1886, by Hugh Fletcher and E. R. Faribault, pp. IP to 163P. 



