T. M. m‘GREGOR on PERTHSHIRE ENTOMOLOGY. 
29 
yellow saliferous sandstone, interbedded with shales containing Old 
Red Sandstone fishes, which occurs in the precipice of the burn of 
Eathie, it is difficult to believe that both the fonnatmi a7id its 
contained fishes were not 7narine. 
In conclusion, we have seen that the case of the “ lake ” theory is 
largely based upon assumptions which may, or may not, admit of 
being proved. The occurrence of inland fresh-water lakes, the 
sudden introduction of numerous genera of fresh-water fishes, the 
unique character of the strata, and the absence of marine fossil 
remains have been freely assumed, whilst supporting evidence is 
conspicuous by its absence. 
We have adduced in favour of the marine view facts showing an 
unbroken physical continuity of the Upper Silurian and Old Red 
Sandstone formations; and we have seen that in the Devonian of 
Russia, and elsewhere, the fishes of the Old Red Sandstone are niarbie, 
while in regard to their introduction and geographical distribution 
the advocates of the “ lake ” theory are ominously silent. 
In other words, subjective theories, on the one hand, have been 
met by objective facts on the other. 
Finally, we believe that the balance of evidence is decidedly 
in favour of the view that the Old Red Sandstone and Devonian, 
in their respective littoral and deep-sea deposits, represent the one 
Devonian system, which is 7na7dne. 
V. —Perthshire E7ito77iology. By T. M. M‘Gregor. 
(Read 12th April, 1894.) 
The science of Entomology has always been a popular study, and 
Coleoptera and Lepidoptera are pre-eminently favourite groups. It 
is admitted, however, by competent authorities that in the whole range 
of entomological science there is no group of insects more interesting 
than another, and no individual life-history, however humble and 
obscure, less worthy of observation than that of its fellow. 
Butterflies and moths have always been favourites, doubtless be¬ 
cause of their conspicuous forms, and the fascination of their gorgeous 
colouring; and because they are our most familiar forms of insect 
life. In lanes and meadows, by the roadside, in gardens and wood¬ 
lands, these “children of the sun” are ever to be met with to brighten 
our path. 
Wild bees, too, are associated with the butterflies in our happy 
memories ; and yet, inseparable as they are, and quite as worthy of 
