Beck_, on the Scales of Lepidocyrtus. 
87 
tions or corrugations upon the surface^, which answer the 
simple purpose of giving strength to very delicate membranes. 
The Podura-scale is^ unfortunately^ no exception to all 
other known objects for the microscope, in not having that 
uniformity which would make it an universal test. I will_, 
however, do all I can, to enable any one who takes an 
interest in the subject, to obtain the proper scale; for as 
yet it has been comparatively seldom mounted for sale. 
The first good specimens that I had ever seen, were those 
supplied by Messrs. Powell and Leaiand; and I can well 
remember, when an accident occurred to one I had long used 
as a test, that I could only obtain another by borrowing a slide 
from a private collection. Subsequently to this, a few could 
be obtained from Mr. Topping, and also from the late Mr. 
George Jackson ; but I have hunted for years without ever 
being able to meet with the right kind myself. I can only 
account for this by my strictly adhering to the directions of 
others, that they were to be found in damp cellars ; whereas, 
I met with them first on a heap of stones out of doors, but 
thoroughly protected by some outhouses, and the best speci- 
mens were not on the damp, but underneath the compa- 
ratively dry stones. After this I found them in an unused 
candle-house, where some old sacking and pieces of wood 
were stowed away in a trough that had been used for chopping 
tallow ; this was in Bedfordshire. I met with them after- 
wards in a hovel in Hertfordshire, amongst old garden im- 
plements and billets of wood, and since then I have found 
a few specimens on some rock- work and in a tool-house 
near London. My own impression is, that the drier the 
place in which you can find the insects at all, the more 
likely will they be to furnish the best scales. I have alto- 
gether mounted some hundreds of slides, and any one who has 
the time for careful search can, I believe, also, obtain them 
in any quantity. Mr. Pritchard^s directions, " to sprinkle a 
little oatmeal or flour on a black piece of paper, and place it 
near their haunts, I have found of no help, for this simple 
reason, that the difficulty is in finding their haunts, after 
which the insects themselves are easily caught; there is, 
however, this simple guide, which deserves notice : — I believe 
the whole family feed either on decaying vegetable matter, or 
on the most minute fungi. 
As the determination of the precise species of Lepidocyrtus^ 
Bourlet [Cyphodeirus, Nicolet), which aff'ords the proper 
test-scales is, I find, attended with considerable difficulty, it 
