with descriptions of new species. 577 
Next take a sheet of fine Bristol-board, and cut it up 
into pieces, say twelve lines by nine, and punch, at one 
end, a round or square hole four or five lines across. On 
the lower side of this fasten, by means of Canadian balsam 
dissolved in benzine, a microscopic cover glass. When 
this has dried fill up half the cell thus formed with the 
same composition, spreading it as evenly as possible, 
and in it arrange your preparation. Put it aside for some 
hours in a place where no dust will fall on it, then fill 
the cell with enough balsam to run over the edge of the 
cell, place a cover-glass over it, and press it down. All 
that now requires to be done is to allow the preparation 
to dry, taking special care to keep it flat, to label it, and 
stick a pin through the card, by means of which it is 
stuck in the cabinet alongside the insect from which the 
part was taken. To examine it under the microscope, all 
that is necessary to do is to place an ordinary glass slide 
across the stage, and place the card on it, in doing which 
it is not necessary to take the pin out of it, if a short pin 
be used. 
The great advantage of this plan for entomological © 
purposes is, that it does not necessitate the formation of 
two distinct collections, which must be the case if dis- 
sections are mounted on glass slides, which cannot, of 
course, be placed alongside the insects. Besides that it 
is cheaper, more expeditious, and safer ; for the cards are 
so light that no injury comes to them from falling, or 
getting loose in the box. If desired, a coloured ring can 
be put round the top object-glass by the turn-table in the 
ordinary way, but, except for ornament, I do not think it 
necessary. I usually prepare two or three dozen of the 
cards with one cover-glass on at a time, so as to have 
them ready for use. I should add that the object of 
letting the dissections harden in the cell half filled with 
balsam is that three or four separate parts may be 
arranged in the most suitable way in the same cell with- 
out fear of their being disarranged or injured when the 
top cover-glass is put on, while both might happen if the 
whole operation was performed at once. I need scarcely 
add that the old barbarous method of using the undi- 
luted balsam—a process requiring the aid of a lamp—will 
not apply here. 
For the examination of the saws I find a quarter-inch 
objective the best ; the teeth in some cases are so fine that 
they are apt to be overlooked if lower powers are used. 
TRANS. ENT. SOc. 1881.—PaRT IV. (DEC.) 4K 
