On a Nevj Geological Formation in Canada. 299 



together with large numbers of the head shields of 

 Audunaspis." 



Tt is impossible to read over the association of forms in 

 the above Ledbury shales of Herefordshire without 

 recognizincf in them the fauna and horizon met with at 

 McArras Brook in Antigonisli County, Nova Scotia. 



In 1843 Dr. Abraham Gesner ^ describes an " Old Eed 

 Sandstone, or Devonian group," which he recognizes 

 above Silurian beds ... in several parts of the Province" 

 . . . consisting of ..." a bright red micaceous sandstone 

 or conglomerate, accompanied by thin beds of red shale 

 and marly clay, and in some places containing seams of 

 fibrous gypsum." He adds : " Hitherto no organic remains 

 have been found in it." He recognizes it at Advocate 

 Harbor and on the Moose Kiver, where it is " seen lying 

 unconformably beneath the Coal Measures." 



In his report Mr. H. Fletcher classifies these rocks 

 of Advocate Harbor as Devonian. The " Old Eed 

 Sandstone or Devonian Group " of Gesner are therefore 

 linked with the rocks of Union and Riversdale, " but, 

 ffom the fauna and Hora found in them, are referable to 

 Carboniferous times, and from their position in tlie strati- 

 gi'aphical succession appear to belong to the Eo-Carbon- 

 iferous. 



In JSTovember, 1899, in a communication on a number of 

 fossil fishes sent him by the writer from various localities 

 in which the geological horizon and precise affinities of 

 the species sent were doubtful, Mr. A. Smith Woodward, the 

 eminent authority on Pakeozoic fishes, gives the following 

 notes ou the specimens which he had previously submitted 

 to Dr. E. Traquair of Edinburgh : — 



" The specimens from McArras Brook are extremely 

 interesting and represent the base of the Lower Old Eed 

 Sandstone of Britain. The Pteraspidian remains are suffi- 

 cient to prove that they belong to the genus Fterasjns. 



1 Pi-oc. Geol. Soc. London, Vol. 4, lait 1, Xo. 95, p. IST, 1843. 



