ILLUSTRATIONS. 



Plate I. 



Fig. 1. Glass cell cemented to plate and ready for grinding. 



Figs. 2-7. Successive positions in grinding a number of the polyscopic cells. 



Fig. 8. The finished polyscopic cell ready for the specimen. 



9. The cell with specimen mounted showing means of holding the object in 

 place therein; ready for microscopical examination. 



Plate II. 



Figs. 1 and 2. Slide devised by the author for holding the cell when microscope 



is inclined. 

 Fig. 3. Photomierogi'aph of $ genitalia of Gulex fatigans Wied., mounted in 

 polyscopic cell, using Zeiss AA objective and No. 3 ocular. 

 4. Lateral view of same mount, the cell having been given a quarter turn. 



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