vu 



LIST OF ILLUSTRATIONS. 



PLATES. 



1. Hydracarina : The Genus Oxus. 



2. Amphora inflexa. 



3. The Eye-plates of Eylais. 



4. Cladonia digitata. 



5. Edmund Johnson Spitta. 



6. Charles Frederic Roiisselet, 



FIGUKES IN THE TEXT. 



3. A New Incandescent Lamp for Microscopical Illumination. 



19. A New Form of Polariser. 



68. The Amatevxr Microscopist in War-time. 



69. The Amateur Microscopist in War-time. 

 81. Microscopic Illimiination. 



84. Microscopic Illumination. 



212. The Measurement of Microscopic Drawings. 



213. The Measurement of Microscopic Drawings, 



230. Parasitic Acari. 



231. Parasitic Acari. 

 233. Parasitic Acari. 



280. Measurement by Graduated Fine Adjustment, diagrams 1-4. 



284. Hind-claws of Cat-flea — Ctenocephalus felis. 



288. The Focus-aperture Ratio, diagram 1. 



289. The Focus-aperture Ratio, diagram 2. 

 291. The Focus-aperture Ratio, diagram 3. 



293. The Focus-aperture Ratio, diagrams 4 and 5. 



303. Sperchon lineatus. 



319. Eucentrum Murrayi, sp. no v., figs. 1-3. 



323. Pleuretra Brycei, var., fig. 4, and Habrotrocha Milnei, nom. 



no v., fig. 5. 

 328. Parasite of Mniobia russeola, fig. 6, a-d. 



