XVlii LIST OF ILLUSTRATIONS. 



PAGE 



47. Stage-Forceps, . . t * . .147 



48. Aquatic Box, . , . . . 



49. Zoophyte-Trough, , . , % - .150 



50. Compressorium, . . V . . 151 



51. Dipping-Tubes, . . ... . . .152 



52. Forceps, . . . . 



53. Section of Adjusting Object-Glass, . .^ . .165 



54. Arrangement of Microscope for Transparent Objects, 



55. Ditto Ditto Opaque Objects, . . .177 



56. Spring Scissors, *V l ' , ;i . . . . . 203 



57. Curved Scissors, ....... 204 



58. Valentin's Knife, . . . 



59. Section-Instrument, ....... 206 



60. Lever of Contact, . . . . . . . 216 



61. Slider-Forceps, . ... . . . . .226 



62. Spring-Press, /' . r & 227 



63. Turn-Table, . V. .,.- . . . 236 



64. Plate-glass Cells, 238 



65. Tube-Cells, 239 



66. Built-up Cells, . . ?r . '. . . 240 



67. Palmoglcea macrococca, after Braun, . . . . .251 



68. Protococcus pluvialis, after Cohu, . , . . 



69. Vblvox globator, after Ehrenberg, . .'" ! . . . 259 



70. Development of Volvox, after Williamson, . . . . 262 



71. Various species of Staurastrum, after Ralfs, .... 266 



72. Closterium lunula, after S. Gr. Osborne, .... 267 



73. Development of Pediastrum granulatum, after Braun, . .271 



74. Various forms of Pediastrum, after Ralfs, .... 



75. Conjugation of Cosmarium botrytis, after Ralfs, . . .274 



76. Ditto of Clostcrium, after Ralfs, . . . . 275 



77. Didymoprium Grevillii, after Ralfs, . . . . .275 



78. Portion of Isthmia nervosa, after Smith, .... 280 



79. Triceratiumfavus, after Smith, ..... 281 



80. Pleurosigma angulatum, after Wenham, . . . . 282 



81. Biddulphia pulchella, after Smith, . . . . .283 



82. Conjugation of Epiihemia, after Thwaites, .... 



83. Conjugation of Aulacoseira, after Thwaites, .... 286 



84. Actinocyclus undulatus, after Smith, .... 289 



85. Heliopelta, . . . . . . . .290 



86. Arachnoidiscus Ehrenbergii, after Smith, . . .. . 291 



87. Campylodiscus costatus, after Smith, . . . . > .292 



88. Surirella constricta, after Smith, ..... 293 



89. Gompkonema geminatum, after Smith, ..... 294 



90. Ditto, * more highly magnified, after Smith, . 295 



91. Licmophoraflabellata, after Smith, . . . . .296 



92. Meridian circulare and Bacillaria paradoxa, after Smith, . . 296 



93. Achnanihes longipes, after Smith, . ,. >k . . 297 



94. Diatoma vulgare, after Smith, . . . . . 298 



95. Grammatophora serpentina, after Smith, .... 298 



96. Isthmia nervosa, after Smith, . ; ' . . . 298 



97. Meloseira subflexilis, after Smith, . . . . .299 



98. Meloseira varians, after Smith, . . . . . 299 



99. Mastogloia Smithii, after Smith, . .' '. ; . . 300 



100. Mastogloia lanceolata, after Smith, ..... 300 



101. Fossil Diatomacece from Oran, after Ehrenberg, . . .302 

 102.. 'Fossil Diatomacece from Mourne Mountain, after Ehrenberg, . 304 

 ID 3. Hcematococcus sanguineus, after Hassal, . . . .308 



104. Development of Ulva, after Klitzing, . . . . 309 



105. Zoospores of Ulva, after Thuret, . . , . . .310 



106. Zoospores of Achlya, after linger, . . . . . 316 



107. Cell-multiplication of Conferva, after Mohl, . . . .318 



