INDEX 



All numbers refer to pages : words in italics are names of families, genera and 

 species : words in thick type are names of higher divisions : words in small 

 capitals are names of examples. Numbers in thick type are numbers of pages 

 on which there are figures : an asterisk after a number indicates a definition 

 of the term or of the group. 



ABACTINAT,, 368*, 410 



Abdomen, of Apus, 519 : Aatacu*, 528 : 

 Periplaneta, 603, 606 



Aboral, 368*, 410 



Absorption, 33 



Aby^.pal species, 8* 



Acantharia, 62, 63, 65 



Acanthin, 63* 



Acanthobdella, 505, 506 . 



Acanthocephala, 293* : External char- 

 acters, '307, 308: Body-wall, 307 : 

 Body-cavity, 307, 398 : Proboscis, 

 308 : Vessels, 308 : Nervous system, 

 308 : Excretory organs, 308, 309 : 

 Reproductive organs, 309 : Develop- 

 ment, 309, 310 



Acanihohamingia, 482 



Acanthometridce, 62 



Acarida, 646, 649, 651, 652, 653, 655, 656 



Accessory female glands, 240*, 265* 



Achro matin, 19* 



Aciculum, 431* 



Acineta, 101, 102, 103 



Accela, 248, 261, 266, 267 



Acontia, 186*, 199, 206 



Acorn-shells, 551 



Actceon, 726 



Actinal, 368*, 410 



Actinia, 191, 223 



Actiniaria, 192*, 194, 195 



Actinobolus, 95, 98 



Actinodactylella, 253, 256, 260, 268 



Actinometra, 416 



Actinomma asterac-tnthion, 63, 64 



Actinophrys sol, 58. 59, 61 



Actinosphcerium, 58, 59, 61 



Actinostome, 369* 



Aclinotrocha, 351, 352, 512 



Actinozoa, 129 : Example, 183 : Dis- 

 tinctive characters and classifica- 

 tion, 191 : Systematic position of 

 example, 194 : General organisa- 

 tion, 1 9 1 : Budding, 195 : Structure 

 of polypes, 196 : Enteric system 

 199 : Fixed and free forms, 199 

 Dimorphism, 200 : Skeleton, 200 

 Colour, 205 : Commensalism, 205 

 Distribution, 207 



Actimda, 223*, 227 



Adamsia palliata, 205, 206 



Adductor impressions, 685, 666, 679, 

 680, 681 



Adductor muscles, 357*, 666, 675, 676, 

 677, 679, 680 



Adhesive cells, of Hormiphora, 213* 

 Turbellaria, 258 



Adinidce, 81 



Adipose tissue, 27*, 28 



Adjusters, 357* 



Adradius, 139 



Adrectal gland, 724 



JEginopsis, 156 



JSginura, 155 



JEquorea, 143 



Affinities See Relationships 



Aijalma, 163 



Agamobium, 141*, 175 



Aggressive characters, in Crustacea, 

 586 



Air-sacs, of Insscts, 627, 628 



Albertia, 328 



Alciopidfp., 477 



Alcippe, 551, 565 



Alcyonacea, 193*, 195, 197, 200 



Alcyonaria, 193*, 194, 195, 197, 199, 

 200, 224 



785 



