INDEX. 



Keferences to directions for the study of forms are indicated by the use of 



bold-faced type for the page number. 



ACANTHOCEPHALA, 59 



Acarida, 154 

 Acineta, 5 

 Acinetaria, 5 

 Acmsea, 113 

 Acridium, 155, 184 

 Actiniaria, 25 

 Actinomjrxida, 4 

 Actinophrys, 1, 7 

 Actinopoda, 1 

 Actinosphserium, 1, 7 

 Actinozoa, 25, 41 

 ^ginopsis, 24 

 ^olis, 113 

 Agalena, 154 

 Alcyonacea, 25 

 Alcyonaria, 25, 43 

 Alcyonium, 25 



Alectrion, 131 



Amaroucium, 195, 203 



Amoeba, 2, 6 



Amoebsea, 1 



Amphidinium, 2 



Amphineura, 112, 130 



Amphioxus, 195, 206 



Amphitrite, 87, 96 



Annelida, 87 



Anosia, 155 



Antedon, 69 



Anthomedusae, 24 



Antipatharia, 25 



Aphis, 155 



Apis, 156, 189 



Aplacophora, 113 



Aplysina, 19 

 Apoda, 69 

 Appendicularia, 195 

 Appendix, 208 

 Arachnida, 153 

 Arachnoidea, 153, 177 

 Araneida, 154 

 Arbacia, 68 

 Arcella, 2, 6 

 Archi-annelida, 87 

 Archi-chsetopoda, 87 

 Arenicola, 87, 98 

 Argonauta, 114 

 Argulus, 152, 175 

 Armata, 87 

 Arthostraca, 153 

 Arthropoda, 152 

 Articulata, 64 

 Ascaris, 59 

 Ascidiacea, 195 

 Ascidian, 197 

 Aspidobranchia, 113 

 Asterias, 68, 69 

 Asteroidea, 68, 69 

 Astrangia, 25, 43 

 Astropecten, 68 

 Astrophyton, 68 

 Aurelia, 25, 37 

 Autolytus, 87, 92 



Balanoglossus, 194, 196 

 Balanus, 152 

 Barnacle, 176 

 Bdelloura, 47, 49 

 227 



