1890.] NEW-YORK MICROSCOPICAL SOCIETY. 11 



be a larger one than usual. Asphaltum will, moreover, only 

 adhere to well-cleaned glass, and may crack with time. Canada- 

 balsam, which always makes a hard and well-adhering frdme, 

 may never dry where it comes in contact with the glycerine, 

 and, if the glycerine layer be not very thin, it will gradually 

 enter under the cover-glass in the shape of a cloudy mass. A 

 glycerine mount framed in Canada-balsam is never safe. It 

 may last for a year or more, but it will eventually deteriorate, 

 as has been my sad experience to witness. 



" The cement I have prepared can be used without fear of 

 any of these difficulties occurring. It is composed of equal 

 parts of hard paraffine (melting point 60° C.) and Canada- 

 balsam. They are melted together in a porcelain evaporating 

 dish, and then kept heated over a moderate flame until the mass 

 becomes of a golden color, and emits no more turpentine 

 vapors. When cold the mixture is hard, but it can be readily 

 warmed for use." 



Mr. Schultze also gave notice of diatomaceous material 

 found by a fisherman, in the month of June last, floating in the 

 Pacific Ocean, two miles off the coast of Santa Monica, Cali- 

 fornia, and stated that the material was now under examination 

 to ascertain if it contained the same forms as those in the 

 original "Santa Monica Find." 



Dr. N. L. Britton read a Paper, entitled "The genus Eleo- 

 charis in North America." This Paper was illustrated by 

 black-board sketches, and by a series of herbarium specimens 

 and mounts as announced below, and is published in the 

 Journal, Vol. V., No. 4, p. 95. 



OBJECTS EXHIBITED. 



1. New and old mandibles of Calotermes marginipeiinis, Latr., 

 and cast skin of the nympha of the same. Prepared by J. 

 Beaumont, Colon, S. A.: Exhibited by P. H. Dudley. 



2. Egg — one day after laying — of Diplax Berenice : by . L. 



RlEDERER. 



3. Larva of the same, five days old : by L. Riederer. 



4. Seeds of Eleocharis mi/tata {l^.), Roem. &: Schult.: by N. 

 L. Britton. 



5. Seeds of ^. capitata (Willd.), R. Br.: by N. L. Britton. 



