328 NATURAL HISTORY OF OUR SHORES 



I have some by me that were prepared thus. A large 

 card (about a foot by eight inches) was covered with black 

 paper. On this cross bands of white paper were pasted, so 

 as to divide it into squares (36). In the corner of each 

 square was neatly written, in white, a number. Then this 

 was photographed down to the required size (one inch long), 

 and a paper print made. This was mounted on a card, 

 lightly gummed, and three shells of each species put on 

 each square, to show the opposite sides and edge of each 

 (or bottom, as the case might be). Another card, with the 

 centre cut out to the size of the mount, was then gummed 

 on, while a very thin, three-inch by one-inch slip formed 

 the cover. 



If the reader is inclined to go to this trouble he will do 

 well to use a photo-mechanical plate and a vigorous de- 

 veloper, so as to get good black and white. Note must also 

 be taken to write the figures " reversedly," for the micro- 

 scope reverses the image. 



For ordinary dry mounting a slip must be put on the 

 turn table, a ring of brown cement spun upon it, and a 

 metal ring of suitable size stuck on. The inside of the cell 

 thus formed must be painted with the " matt black," and, 

 when dry, just lightly gummed, so that the shells will 

 adhere when it is breathed upon. All being satisfactorily 

 in place, a narrow line of brown cement is made on top of 

 the metal ring, and allowed to set. A cover, just a shade 

 smaller than the metal ring, is then made hot, and put on ; 

 it will stick fast, and the cement will not run on the under 

 side of the cover, as it would do if put on while the cement 

 was liquid. 



A ring of brown cement is now spun around, covering 

 that part of the cover which lies on the metal, for the sake 

 of neatness, and well filling the angle made by the metal 

 ring and the slip. Finish with black. 



To mount Foram Shells in Balsam, This is usually done 



