THE NAUTILUS. 45 



its ruled surface with gum arabic laid on smoothly with a brush. 

 When dry it is cut into gummed tags * 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 is an easy tiling now when lam 

 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 2|X2, 4X2i, 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 i 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 

 2i 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 

 Heli.c tridenlata. For the smallest boxes the vials are 1 1 inches long 

 and about 1 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, Vvrtigo Pupa, etc., 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 3x1 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 3x1 

 inch glass slips used by microscopists, those with rough edges pre- 

 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. 



