742 Rev. C. R. N. Burrows on the 
the subject, and I am left with our preparations and 
specimens, Mr. Pierce’s photographs, and the drawings 
which were so skilfully executed under Mr. Tutt’s eye by 
Mr. Gatter, who has kindly sent them on to me. 
In dealing with our material, Mr. Pierce and I found 
ourselves faced at the outset by a great difficulty. The 
likeness of these four species to one another is so extreme 
that although long series have been exhibited privately 
to experts, and publicly to most of the London, and some 
of the Provincial societies, no one has yet been able to 
point out a single feature by which they can be visually 
separated with certainty. 
In size the imago of nictitans is perhaps the smaller. 
Crinanensis is a little larger, paludis from a little to 
considerably larger, and /ucens generally much larger. 
The colour of the fore-wings is as confusing as is the 
size. Paludis is usually of a dull yellow-brown, and by 
colour alone can generally be separated from the others. 
I have no specimen of the other three species quite this 
colour, they being always tinged with red, but both 
nictitans and lucens occasionally come very near to it. 
I have all four species quite red, but when paludis is red 
it remains still quite a different insect from Jucens in 
appearance. Crinanensis is commonly very dark, sometimes 
almost melanic, but I have nictitans (from Scotland) almost 
as dark, and also paludis from my own garden. There is 
a tendency to the formation of a central dark band on 
the fore-wings in the lighter specimens, less common in 
nictitans but common in the rest. In shape of fore-wings 
all four species agree, the pointed apex being perhaps less 
marked in nictitans and crinanensis. In wing markings, 
also, all are alike—I should perhaps say, more correctly, 
that there is no one mark belonging to one species which 
is not to be found upon the others of the group. The 
orbicular stigma, for instance, is more generally distinct in 
nictitans, it is rarely distinct in paludis, often distinct in 
lucens, and frequently so in erinanensis. The reniform 
stigma is always full (that is to say, possesses the inner 
circumference toward the base of the wing) in nzctitans, 
in crinanensis it is often almost full, in lucens and paludis 
it is never full. But all four forms have frequently the 
reniform stigma suffused, smudged, or ill-defined, owing 
to the absence of the fine interior lines, The same re- 
semblance also appears in the colour of the stigmata, which 
