Robert Campbell — South-Eastern Kincardineshire. 67 



of the stone raised, on the counterpart incised. These markings are 

 at once suggestive of the middle layer of the Pteraspidian shield, but 

 in none of the specimens is any trace found of the inner layer or of 

 the outer layer with its markings. More likely does it seem that 

 these films are of the same nature as the problematic Dietyocaris of 

 Salter from the Upper Silurian of the Pentland Hills, which occurs 

 in similar blotch-like masses and shows very similar polygonal 

 markings. 



" As to whether the Cowie fish-remains indicate a Lower Devonian 

 or an Upper Silurian (Downtonian) horizon, they in themselves afford 

 no certain answer to the question, beyond this, that Cyathaspis, 

 although it occurs in Lower Devonian rocks, seems, according to 

 number of species, to be more characteristically a Silurian genus. 

 If, therefore, the associated invertebrate remains favour the reference 

 of these beds to the Downtonian horizon, that idea would be 

 corroborated rather than the reverse by the relics of fishes noted 

 above." 



Apart from plant-fragments, worm-tracks, and Dietyocaris the 

 remaining fossils belong to the Arthropoda. They include Ceratiocaris 

 sp. (carapace, rostrum, and cercopod) ; Archidesmus sp. and a new 

 genus of Myriopod ; (?) larval form of insect ; Eurypterns, sp. nov. ; 

 fragments of scorpion. These Arthropoda will be described by 

 Dr. Peach, to whom I am indebted for the above provisional 

 determination. 



Although the typical Downtonian fishes of the south of Scotland 

 have not so far been met with in Kincardineshire, yet the occurrence 

 of Ceratiocaris and Dietyocaris, neither of which has hitherto been 

 found in rocks younger than Upper Silurian, would appear to indicate 

 that these Cowie beds are of Downtonian age. This view, as pointed 

 out by Dr. Traquair, is apparently corroborated by the association of 

 these fossils with Cyathaspis. 



Since I returned to Edinburgh I have learned from Dr. Home that 

 in 1881 Mr. MacConnochie, of H.M. Geological Survey, collected from 

 the ' Stonehaven Beds ' on the shore near Cowie, and from the 

 prolongation of the same beds exposed in the Carron Water, west of 

 Tewel, specimens of Dietyocaris, together with fragments of Pterygotus, 

 Enrypterus, and (?) Kampecaris. From the abundance of the remains of 

 Dietyocaris Dr. Peach at that time suggested that the beds containing 

 these fossils might be of Upper Silurian age. 



2. In the excellent account of the volcanoes of Lake Caledonia 

 in his Ancient Volcanoes of Great Britain, Sir Archibald Geikie l 

 has correlated the initial outbreak of volcanic activity with the coming 

 on of the conditions which gave rise to the massive quartzite 

 conglomerate south of Stonehaven Harbour. That volcanoes were 

 active in this area at a much earlier period is seen from the great 

 development of tuffs and volcanic conglomerates in the Downtonian 

 sequence. The lowest volcanic conglomerate is about 2,500 feet below 

 the above-mentioned quartzite conglomerate. It can be traced inland 

 until it is lost against the Highland fault, and everywhere the 



1 Ancient Volcanoes of Great Britain, vol. i, p. 303. 



