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. 



A, 



A 



.BACTIXAL, 347* 



Abdomen, of Apns, 489; A-yfacus, 498; 

 Periplaneta, 51'2, 574 



Absorption, 32 



Abyssal species, 8 



Acanthocephala, 275* : External charac- 

 ters, 290 : Body-wall, 290 : Body- 

 cavity, 290 : Proboscis, 290 : Vessels, 

 291 : Nervous system, 291 : Excretory 

 organs, 292 : Reproductive organs, 

 291, 292 : Development, 292 



Acarida, 612*, 616, 618, 619, 620, 621 



Achromatiii, 15* 



Aciculum, 405* 



Acineta, 90, 91, 92 



Accda, 252 



Acontia, 175, 188 



Acorn- shells, 534 



Actinal, 347* 



Actinia, 180, 214 



Actiniaria, 181, 183, 185, 188 



Actinobolus, S4, 85 



Actinodactylella, 244, 245, 25o 



Actinometra, 392 



Actinomma asteracanthion, 60 



Actiiiofthrys sol, 55 



., 1 1'linnxftlin ri/nu, 56 



Actinostome, 347* 



Acfinotrochu, 330, 462 



Actinozoa, 118*: Example, 172: Dis- 

 tinctive characters and classification, 

 180 : Systematic position of example, 

 183 : General organisation, 183 : Bud- 

 ding, 184 : Structure of polypes, 185 : 

 Enteric system, 188 : Fixed and free 

 forms, 189 : Dimorphism, 189* : Skele- 

 ton, 189 : Colour, 195 : Commensalism, 

 195: Distribution, 196 



Adamsia palliata, 195, 196 



Adductor impressions, 633, 634, 650 



Adductor muscles, 635, 648, 645, 646, 

 647, 649 



Adhesive cells, of Hdvfaniphora, 202 : of 

 Turbellaria, 248 



Adipose tissue, 23*, 25 



Adradius, 129 



Adrectal gland, 693 



^E<jino}i*is, 144 



^Eginura, 143 



jEyir, 188 : Addenda 



./:'// nor ea, 133 



Affinities See Relationships 



Atjalma, 151 



Agamobium, 130 



Aggressive characters, in Crustacea, 555 



Air-sacs, of Insects, 593, 594 



Albertia, 309 



AIciojiii./H', 447 



Alcippe, 522; 534 



Alcyonacea, 182*, 195 



Alcyonaria, 182*, 187, 188, 197 



Ah'youidium, 320 



Alcyonium, 182, 190 



Alecithal, 206* 



Alimentary canal See Digestive system 



Alimentary system See Digestive s j T stem 



A/pheus, 556 



Alpine forms, 8 



Alternation of generations See Meta- 

 genesis 



Alveolus, of Sea-urchin, 366 



Ambulacral grooves, 347* 



Ambulacra! ossicles, 349 



Ambulacral pores, 349 



Ambulacral system, of Axfci-iti*, 350 : 

 Ecliiiinx, 367 : Sea-cucumber, 370, 371 : 

 of Antedon, 375 : of Echinodermata, 

 393 



3 C 2 



