THE PREPARATION AND MOUNTING OF FORAMINIFERA. 197 
view without loss of time in searching over the same portions many 
times, and perhaps entirely omitting others. It is surprising what a 
quantity of sand can thus be looked over in a short time, by this 
systematized labour. 
Supposing the shells are clearly seen among the sand, how are 
we to get them? ‘There is no royal road that I know of, they 
must be picked out singly. I use for this purpose a very fine 
needle set in a suitable handle. The point of the needle is dipped 
in turpentine, and when a shell is touched by it, it adheres and 
may be lifted out and deposited in a small vial, or upon the slide 
where it is to be mounted. I have a board about 6 by ro inches, 
and 1 inch thick, in which rows of holes are bored nearly through. 
In these holes little half dram vials are placed. The vials are 
labelled with the names of the different species of Foraminifera, 
and when a shell is found it is picked up as described above, and 
with a little flip of the needle against the neck of the appropriate 
vial it is shaken off and preserved for future use. Sometimes I 
put all I find into one vial and then sort them out into their 
respective vials at my leisure. In place of the needle used as 
above, I sometimes employ a very small camel’s hair brush, 
moistened and drawn to a delicate point by the lips. This is per- 
haps best for very delicate shells which might be broken by the 
needle. Of course, these manipulations will be difficult to the 
beginner till he learns how to use the needle under the objective, 
for he must remember every thing is reversed from what it 
appears. 
The shells being obtained, how shall they be mounted? Very 
many of the species of Foraminifera, especially the younger shells, 
become so transparent when immersed in turpentine or balsam 
that they may be viewed by transmitted light. To mount them in 
balsam, the shells should be soaked in turpentine till all the air is 
driven out of the cells. Then they may be transferred to a slide 
with a cell deep enough to keep the cover glass from resting on 
them and which is filled with z#zz balsam. In this they can be 
arranged in position to display them properly. The slide should 
then be put away to permit the balsam to harden. Care should be 
taken to keep out the dust and that the balsam does not dry away 
from the shells and permit the exposed portions to fill with air. 
When the balsam has hardened, a drop of turpentine may be spread 
over the top and a fresh coating of balsam added. This may be 
repeated till the cell is full when with the last coat, or layer, of 
balsam the cover glass may be put on. This process may be greatly 
facilitated by the use of heat, but care is necessary to retain the 
shells in position, and such slides should be left lying flat. 
Such mounts well repay the time and labour required in their 
preparation, for they not only serve for study with transmitted, but 
