Preparatory to corking the glass for the specimens assigned to it, the spaces required for them are to be ascertained by arranging them in order on a cork surface or otherwise. On a sheet of paper of the size of the glass, perpendicular lines, of the number of the rows and at their proper distances, are to be drawn, and cross lines equal in number to the insects contained in the rows. The distances of these lines will be uniform, unless smaller specimens are to occupy some portion of the case, when they may be graduated to the required proportion. With the sheet ruled in this manner and placed beneath the glass, the points where the corks are to be applied are indicated by the intersections of the lines. The sheet, marked with the family of the insects for which it was used and with the numbers designating its divisions, may be laid aside for future use in the preparation of other cases for which it may be suitable. In a series of unbound cases in my collection, in which the glasses measure 11 by 141/2 inches, I have used for my Lepidoptera and laid aside the following scales, the citation of which will also serve to show the capacity of the cases: 3 by 8, Catocalas; 2 by 7 and 3 by 9, Sphingidae; 4 by 11 to 4 by 14, Bombycidae; 5 by 13 to 6 by 16, Noctuidae; 8 by 16 and 8 by 20, Lycaenidae and Tortricidae. The unbound cases above referred to are inexpensive frames, made by myself, of quarter-inch white wood or pine, the corners mitered, glued, and nailed with three-quarter inch brads, lined within with white paper (better with tin foil), and covered without with stout manila paper. The glasses are cut of the size of the frame, and when placed in position thereon are appressed closely to it by laying upon them, near each corner, a heavy weight, and strips of an enameled green paper, cut to the width of 1 inch, are pasted over their edges, extending a little beyond the thickness of the frame, and brought downward over the outside of the frame. On its back two gum labels, indicating the insects inclosed, are placed at uniform heights (7 and 12 inches), when, if all has been neatly done, they present a tasteful appearance upon a shelf. When there is reason to believe that the case will need to be opened for the change or addition of specimens, it will be found convenient to employ, for the fastening of the left-hand side of the upper glass, paper lined with a thin muslin, to serve as a hinge when the other sides have been cut. Should it become desirable to bind these cases, outside frames may be constructed after the plans above given, with the omission of the inside quarter inch (the equivalent of these frames), in which these may be placed and held in position by two or three screws inserted in their sides.