Appendix B. 375 



The skimmings should be well washed in the sieve and dried, 

 when the ostracoda can easily be picked out with a hand lens 

 and camel-hair pencil. In the dry state a series of brass or 

 copper wire sieves will facilitate the work greatly ; a set of four, 

 fitting into each other, suits very well, the largest being five 

 and a half or six inches in diameter, and an inch in depth, and 

 the rim of each projecting a little under the bottom, so as to 

 leave space for what passes through the different sieves. The 

 uppermost sieve should have a mesh of twelve wires to the inch, 

 the next twenty-four, the next thirty-six, and the undermost 

 seventy-six to the inch, which is sufficiently fine to retain all the 

 ostracoda. The first or uppermost sieve retains few or no 

 ostracoda, but removes all the coarse material. In most cases 

 a great deal of vegetable fibre remains in the sieves, and may 

 be blown off, but this must be done carefully, so as not to blow 

 away any of the smaller ostracoda."" Fresh and Brackish- 

 Water Ostracoda," pp. 28-30, 33-35. 



