INDEX. 



References to directions for the study of forms are indicated by the use of bold- 

 face type for the page number. 



ACANTHOCEPHALA, 57 



Acarida, 150 

 Acineta, 4 

 Acinetaria, 4 

 Acmaea, 110 

 Acridium, 151, 179 

 Actiniaria, 23 

 Actinomyxidia, 3 

 Actinophrys, 1, 6 

 Actinopoda, 1 

 Actinosphserium, 1, 6 

 Actinozoa, 23, 40 

 ^Eginopsis, 22 

 jEolis, 110 

 Agalena, 150 

 Alcyonacea, 23 

 Alcyonaria, 23, 41 

 Alcyonium, 23 

 Amaroecium, 191, 199 

 Amoeba, 1, 5 

 Amoebina, 1 

 Amphineura, 109, 127 

 Amphioxus, 191, 202 

 Amphitrite, 84, 93 

 Annelida, 84 

 Anosia, 151 

 Antedon, 67 

 Anthomedusae, 22 

 Antipatharia, 23 

 Aphis, 151 

 Apis, 152, 185 

 Aplacophora, 110 



Aplysina, 17 

 Apoda, 67 

 Appendicularia, 191 

 Appendix, 204 

 Arachnida, 149 

 Arachnoidea, 149, 173 

 Araneida, 150 

 Arbacia, 66 

 Arcella, 1, 6 

 Archi-annelida, 84 

 Archi-chsetopoda, 84 

 Arenicola, 84, 95 

 Argonauta, 111 

 Argulus, 148, 171 

 Armata, 84 

 Arthostraca, 149 

 Articulata, 62 

 Ascaris, 57 

 Ascidiacea, 191 

 Ascidian, 193 

 Aspidobranchia, 110 

 Asterias, 66, 67 

 Asteroidea, 66, 67 

 Astrangia, 23, 41 

 Astropecten, 66 

 Astrophyton, 66 

 Aurelia, 23, 35 

 Autolytus, 84, 89 



BALANOGLOSSUS, 190, 192 

 Balanus, 148 

 Barnacle, 172 

 223 



