FAUNA OF THE FORMATION 309 



Mr Fletcher adds : 



" This section is only approximate. It represents only a small portion of meas- 

 ures, apparently as thick as at Union; seen also in Knoydart brook and other 

 streams of the vicinity. It is not supposed that either the base or the summit of 

 the series is here given." 



Name and Fauna of the Knoydart Formation 



The name " Knoydart formation " is proposed for the series of strata 

 of which the 684 feet recorded above constitute a characteristic section 

 holding a typical " Old Red Sandstone " fauna. This name is given in 

 order to be able to better designate the strata in question and separate 

 them from other Paleozoic formations in that portion of eastern Canada 

 where the sedimentation has a wonderfully close resemblance to Euro- 

 pean types. This striking resemblance to the European succession is a 

 feature which has been pointed out by Sir William Dawson, Salter, 

 Billings, Honeyman, and other writers. 



The following species of fossils obtained from the above strata are 

 provisionally recorded as, characteristic of the Knoydart formation. 

 These and other forms will, no doubt, sooner or later be found in other 

 parts of Antigonish, in Pictou, and in other counties of eastern Canada 

 along the Atlantic border of the continent. The fossil ostracoderms, which 

 constitute a very primitive and early type of fishes, were identified by 

 our friend Doctor A. Smith- Wood ward, of the British Museum, and to him 

 is due the credit of identifying the fish' fauna and indicating the precise 

 geological horizon to which to refer the beds, while the remains of 

 Pterygotus were submitted to and identified by Doctor Henry Woodward 

 when Keeper of the British Museum. 



1. Pterygotus sp. 



2. Onchus murchisoni Agassiz. 



3. Pteraspis sp. cf. Pteraspis crouchli. 



4. Psammosteus sp. cf. Psammosteus anglicus Traquair. 



5. Cephalaspis sp. Probably a new species. 



6. IcJithyoidichnites acadiensis nobis. Impressions made by a pair of sharp- 

 pointed organs or spines, probably those of a fish. 



The specimens are for the most part imperfectly preserved in a hard, 

 compact, fine grained, and brecciated volcanic ash-bed, and are conse- 

 quently difficult to identify and obtain. 



Barlow^ 's Description of Volcanic Ash Rock 



With a view of ascertaining the exact nature of the rock materials in 

 which the pteraspidians were preserved, microscopical sections were pre- 



XLIV— Bull, Geol. Soc. Am.. Vol. 12. 1900 



