340 Proceedings of the Royal Society of Edinburgh. [Sess. 
the Upper Old Red Sandstone, with its characteristic genera, Asterolepis, 
Psammosteus, Bothriolepis, Holopty chius, etc., he correlated with that of the 
Upper Devonian of the north-west of Russia, the Fammenien of Belgium, 
and the Catskill of the United States. 
But Dr Traquair was not content with this broad classification of the 
formation in three divisions. He pointed out the existence of three fish 
faunas in the Middle Old Red Sandstone of Caithness (Achanarras, Thurso, 
and John o’ Groats), each with a more or less distinct assemblage of fishes. 
He correlated the lowest or Achanarras fauna with that near the base of 
the middle division at Cromarty and on the south side of the Moray Firth. 
When Dr Flett subsequently found a similar sequence of fish remains in 
the Old Red Sandstone of the Orkneys, it seemed to confirm the accuracy 
of Traquair ’s conclusions in a remarkable degree. But the recent detailed 
work of the Geological Survey in Caithness has demonstrated the existence 
of a fish fauna older than any of those recognised by Dr Traquair, yielding 
Thursius macrolepidotus, Coccosteus decipiens, and Dipterus Valenciennesi. 
This discovery profoundly impressed Dr Traquair, for he wondered how 
this fauna should appear in the lower part of the Caithness succession and 
yet be absent from the base of the series in the Moray Firth basin and in the 
Orkneys. This difficulty has been successfully overcome by Mr Carruthers, 
who has suggested that it points to a later submergence of the land areas 
in the region of the Moray Firth and the Orkneys. 
With the assistance of Mr Taylor, Lhanbryde, Dr Traquair recognised 
three life-zones in the Upper Old Red Sandstone on the south side of the 
Moray Firth; the lowest being represented by the Nairn sandstones with 
Asterolepis maxima , the second by the Alves sandstones with Psammosteus 
Taylori, and the highest by the Rosebrae sandstones with Holoptychius 
nobilissimus. 
Throughout his long career he published upwards of 130 papers, 
chiefly on fossil fishes, which have appeared in the monographs of the 
Palseontographical Society, the Transactions of the Royal Society of Edin- 
burgh, and the Proceedings of the Royal Physical Society. His great 
monographs on the Palaeoniscidae and the Asterolepidse, which appeared in 
successive instalments in the publications of the Palseontographical Society 
between 1877 and 1912, are still incomplete. He had begun for the 
Geological Survey a synopsis of his researches on the Old Red Sandstone 
fishes of Scotland. He was anxious to finish it for the guidance of younger 
men, but the infirmities of age prevented it. In the closing years of his 
life he prepared a memoir on the Wealden fishes of Bernissart, Belgium, 
published in 1911 by the Royal Museum of Natural History, Brussels. 
