On the Occurrence of Arthrostigma gracile. 111 
Old Red Sandstone species. One would therefore be inclined 
to think that the rocks which contained these fossils should 
rather be referred to the Lower Old Red Sandstone than to 
the Silurian formation. 
Stur places his Lessonia in the Laminaria. I altogether 
doubt the algal affinity of his fossils, and if my suspicions 
are correct as to the nature of his specimens, they must be 
referred to the Lycopodiacee. 
In any case, in absence of fructification, it is unsafe to 
refer Stur’s fossils to any existing order of Algz. 
EXPLANATION OF PLATE. 
Figs. 1-4. <Arthrostigma gracile, Dawson; from the Lower Old Red 
Sandstone of Perthshire. 
XI. Notes on the Devonian Fishes of Campbelltown and 
Scaumenac Bay in Canada. Part I. By R. H. Traquair, 
Ksq., M.D.,,LL.D.,.F.BS., F.G:S. 
(Read 15th March 1893. ) 
Mr Damon, of Weymouth, havine recently received a 
third consignment of fossil fishes and fish remains from 
the Devonian rocks of Canada, an interesting selection has 
been made for the Edinburgh Museum, and I am thus 
enabled to contribute some additional notes regarding the 
palzozoic ichthyology of this region. The specimens were, 
as before, collected by Mr Jex. 
FISHES FROM THE LOWER DEVONIAN OF CAMPBELLTOWN. 
Protodus Jexi, A. S. Woodward. 
Geol. Mag., dec. iii., vol. ix., 1892, pp. 1, 2, pl. i., figs. 1, la. 
A great many specimens of this tooth have been last 
summer collected by Mr Jex. That it is a selachian tooth 
is proved beyond doubt, not merely by its shape, but by its 
