INDEX 



Names of genera and species are printed in italics. 



The figures in thick type refer to illustrations upon the pages indicated. 

 References to details of illustrations are only given in special cases. 



When the first of several figures after a word is followed by a semicolon 

 it indicates the principal reference to the subject. 



An asterisk (*) signifies that some of the series of figures which immedi- 

 ately follow it refer to particular genera only. 



Reference to the summaries of the characteristics of the groups is only 

 made when information there given is not to be found elsewhere. 



Where the passage referred to extends over more than one page, as a rule 

 only the first page is indicated. 



Abambulacral surface, 623 



Abdomen, of Arachnida, see Opis- 

 thosoma ; of Arthropoda, 308 ; of 

 Crustacea*, 308, 330, 331, 332, 

 333, 353, 358, 360, 364, 368, 370, 

 372, 380, 385, 386, 387, 389, 395, 

 400, 403, 404, 410, 415; of In- 

 secta*, 308, 430, 457, 458, 460, 

 483, 486; of lulus, 424; of Poly- 

 chaeta, 270 



"Abdomen" of Tunicata, 674, 677 



Abdominal limbs, of Crustacea*, 

 328-9, 331, 339, 360, 388, 391, 397, 

 401,410, 4i5;ofInsecta, 431,458, 

 459, 463, 465 ; of lulus, 424 



Abdominal region of Balanoglossus, 

 664 



Aboral aspect, side, or surface, 143 ; 

 of Echinodermata, 623 



Aboral sinus system, 626, 627, 650 



Acantharia, 80, 81 



Acanthobdella,.20o; 261, 296, 299 



Acanthobdellidae, 300 



Acanthocephala, 258; 197, 244 



Acanthocystis, 40 



Acanthometra, 81 ; elastica, 82 



Acanthosoma, 335 



Acarina, 533; 517, 520 



Accessory nidamental gland, 591 



Acephalous larva, 508 



Acerentomum doderoi, 465 



Aciculum, 266 



Acineta, 116; 8, 9; grandis, 9; lem- 

 narum, 9 



Acmaea, 552, 563 



Acmaeidae, 565 



Acoela, 213, 215 



Acoelomate Triploblastica, 197 



Acontia, 189 



Acrothoracica, 382 



Actaeon, 564, 567 



Actinia, iSj ; mesembryanthenium, 187 



Actinoceras, 604 



Actinometra, 654 



Actinomma, 81 



Actinomyxidea, 102; 100 



Actinophrys, 83 ; 27, 33 n. ; sol, 84, 85 



Actinosphaeriwn, 86; 10, 20, 23, 28, 

 33, 40, 42, 83 ; eichhorni, 23, 42 



Actinotrocha larva, 622; 145, 621 



Actinozoa, 180; 153 



Actinula larva, 159 



Actipylaea, see Acantharia 



Adambulacral ossicles, 636 



Adambulacral spines, 636 



Adductor muscles, of Cirripedia, 

 379; of claws, 142; of Concho- 

 straca, 354; of Crustacea, 333; of 

 Lamellibranchiata*, 142, 573, 585; 

 of Leptostraca, 390 



Adelea, 89 



Adephaga, 493 



Adoral wreath, 104 



Aega, 398 ; psora, 399 



Aeolosoma, 293 



Aeschna, 444; cyanea, 473 



Aesthetascs, see Olfactory hairs 



Aesthetes, 549 



Afferent branchial vein, 581 



Afferent canals, see Inhalant canals 



Agametes, 37 



Agamogony, 37; 88 



