METHODS OF STUDY 29 



thick, 4x6 paper, which can then be used as 4x6 file card with 

 any notes that may be necessary. 



By the methods outlined here, we have photographed 2,500 

 specimens of foraminifera in an afternoon on less than a hun- 

 dred slides, and had the negatives ready for printing in the 

 evening if necessary. 



The longest time is spent in mounting the slides for photo- 

 graphing, but if flat slides are used with a black background 

 gummed ready for use, one quickly becomes very expert in 

 placing the specimen in position and arranging a number in 

 the 5-millimeter circle. Specimens of fairly uniform size should 

 of course be mounted together to insure uniform focus. 



This method proved by several years of constant usage here 

 in the laboratory will be found a very valuable one wherever 

 numbers of foraminifera are handled, and where permanent 

 records are desired. 



The only changes that have been made in the apparatus de- 

 scribed is to increase the length of the bellows to gain a greater 

 magnification and therefore obviating so much secondary en- 

 largement. As a consequence the camera is used in a horizontal 

 position. 



Sections in many specimens are very necessary for the study 

 of the structure of the wall and of the early stages. They may 

 be made by infiltrating the specimen with balsam and when hard, 

 grinding it down upon an ordinary hone until the desired plane 

 is reached. It may be left in this condition, or softened, turned 

 over and ground down to a thin section according to the par- 

 ticular need. Larger specimens in matrix may be treated the 

 same as in the making of ordinary rock sections. 



In describing foraminifera the following outline is oflfered 

 as that which the writer has long used ; general appearance, 

 chambers, sutures, wall, aperture, and color. These five or six 

 distinctive groups of descriptive characters are set off from one 

 another by semicolons for clearness. 



1. General appearance will include : relative size, propor- 

 tions, characters of the periphery, changes in plan of develop- 

 ment, condition of attachment, and such other general points as 

 are not included in the following more detailed characters : 



2. Chambers, including number, relative size and shape, and 

 arrangement. 



