THE NAUTILUS. 45 
its ruled surface with gum arabic laid on smoothly with a brush. 
When dry it is cut into gummed tags 3 inch wide and 1 inch long 
with which the sides of the trays are fastened together on the out- 
side. Of course this is a little tedious and I found it best to set my- 
self the task of making one dozen a day, and very soon accumulated 
several gross of assorted sizes, and it isan easy thing now when Iam 
short of any particular size, to replenish the stock. 
The cards to make the size of boxes given in this report should be 
cut to the following sizes 232, 4x23, 4x3, 4x3, 4x4, 4x7, and 
7x7. They will give an appearance of uniformity to the drawers 
and save a great deal of space. I usually place a card 3 inch in 
width to just fit the inside of each tray, ruled on the top and bottom 
red lines, this is for the name, authority, and locality of specimens, 
and other data. All shells whose size will admit of it I enclose in 
glass vials, square at the bottom and with no neck, they are about 
2% inches long so that the cork takes up the balance of the space in 
the tray, and of a width to enable them to hold such specimens as 
Helix tridentata. For the smallest boxes the vials are 14 inches long 
and about + inch in thickness. Here, in New York, they can be 
bought for about 50 to 70 cents a gross. 
For the reception of the smallest species, Vertigo Pupa, ete., and 
in order to bring the characteristics of these minute shells promi- 
nently before the observer, I adopted the following plan: Equidistant 
from the sides of a 3><1 inch slip of card board I punched a hole with 
a die, made for the purpose; and then gummed this slip to another 
of equal size on which the surface beneath the whole was covered 
with black paper. The specimens were then mounted with gum in 
this depression and the whole covered with one of the ordinary 51 
inch glass slips used by microscopists, those with rough edges pree 
ferred. The whole thing was then bound around its edges with slips 
of gummed paper 8 inches long by about + wide and the edges trim- 
med with scissors when dry. This plan also protected the shells from 
dust and worked capitally when examining their apertures under a 
low microscopic power, a very necessary proceeding when determin- 
ing or explaining to others the difference in the various species. 
The gum I found best adapted for mounting the shells was picked 
gum arabic—a saturated solution in water mixed with an equal quan- 
tity of glycerine, then filtered and a few drops of acetic acid added, 
this never cracks, nor shows any objectionable gloss. Want of space 
has compelled my relinquishing this plan, for the smallest size trays 
and vials, which, however, I have never found as convenient. 
