On Cephalaspis magnifica from the Caithness Flagstones. 269 
XVII. On Cephalaspis magnifica, a new Fossil Fish from the 
Caithness Flagstones. By R. H. Traquair, Esq., M.D., 
LL.D., F.R.S. [Plate VII.] 
(Read 20th December 1893. ) 
Fishes of the family Cephalaspide are, as is well known, 
especially characteristic of the uppermost Silurian and 
lowermost Devonian rocks. Only one solitary species 
(Cephalaspis laticeps, Traq.) has occurred in the Upper 
Devonian of Canada. . 
But though the family is well represented in the Lower 
Old Red Sandstone of the West of England by species of 
the genera Cephalaspis, Auchenaspis, and Didymaspis, and 
though Cephalaspis is the most characteristic genus of fossil 
fish in the corresponding rocks of the central area of Scotland, 
not a single remnant of a Cephalaspidian had ever been 
found in that great Orcadian area of Old Red Sandstone, 
which includes all the rocks of that formation north of the 
_ Grampian Mountains, and is supposed to have been 
deposited in the hypothetical Lake Orcadie. Notwith- 
standing the richness of the fish-fauna of these rocks, 
Cephalaspide have hitherto been conspicuous by their 
absence. It was, therefore, with a feeling of agreeable 
surprise that, in the month of August of this year, I re- 
cognised in a fossil deposited in the office of the Caithness 
Flagstone Company at Thurso, and recently discovered by 
their workmen in the great pavement quarry at Spital, © 
about ten miles inland, a veritable Cephalaspis, of unusual 
size for the genus, and belonging to an undescribed species. 
On learning my opinion of its importance, the officials of 
the company, with characteristic public spirit and generosity, 
at once presented this specimen to the Edinburgh Museum 
of Science and Art. 
Accordingly, at the meeting of the British Association, 
which was held at Nottingham in the following September, 
I announced this discovery, and briefly described the 
1See Sir A. Geikie’s paper On the Old Red Sandstone of Western 
Europe—Trans. Roy. Soc. Edin., vol. xxviii., 1878, p. 354. 
