INDEX 



601 



Anurcea squamula, spines on loricse of 



45. 



anus in Triarthrus, 209. 

 Aphaneropegmata, 242. 

 Apteryx australis, vestiges of wings in, 



85. 



Apus, 185, 186, 187, 188, 203, 209, 210, 

 211, 215. 



development of, Balfour, 189. 



nauplian features of adult, 189. 



nauplius of, 164, 191. 



studies of, Bernard, 118. 



under side of head of, 210. 

 arachnids, trilobites and limuloids 



classed with, 109. 

 archenteron in Cistella, 248. 

 Archiaspides, Haeckel, 112, 113. 

 Arctinurus, 150. 



glabella in, 150. 

 Areia, 153. 



cephalon in, 154. 

 Arethusina, 113, 148, 178. 



archaic eye-lines in, 148. 



eye-line in, 223. 



fixed-cheeks in, 148. 



Konincki, youngest specimens of, 



177. 

 Arges, 150, 151, 174. 



consanguineus, Clarke, 174. 



extremes of spinosity in, 56. 



eyes in, 126. 



glabella in, 1 50. 

 Argiope, 238. 



Arraphus based on Harpes, 137. 

 Artemia, first pair of appendages of, 



191. 



Arthropoda, accelerated development of 

 spines in, 22. 



extinct, 183. 



geological range and distribution 



of, 184. 



Arthropomata, Owen, 242. 

 Articulata, absence of anal opening in, 

 264. 



Adouin's law regarding, 83. 



Huxley, 242. 



spine production in, 13. 

 articulates, classification of, Haeckel, 



112. 



Asaphdindi 142, 145. 

 Asaphelhts, 146. 

 Asaphida, Haeckel, 112. 



Asaphidge, 129, 131, 139, 146. 



defined, 145. 

 Asaphiui, 134, 139, 152. 

 Asaphiscus, 146. 



Asaphus, 116, 129, 145, 146, 222. 

 a normal trilobite type, 128. 

 free cephalic segments in, 118. 

 glabella in, 135. 

 gnathobases of, 207. 

 pleural spines in, 80. 

 Aspergillum, 237. 



Aspidonia, Merostomata included in, 

 112. 



Trilobita classed with, 112. 

 Astacus, embryos of, 192. 

 Asteroidea, compound spines in, 68. 

 development of tubercles of, into 

 spines, Wachsmuth and Springer, 

 50. 



smooth surface in early, 25. 

 spine growth in, 69. 

 Astragalus Tragacantha, leaves of, 

 transformed into spines, 75. 



spiniform leaf axis of, 73, 75. 

 Astropilium elegans, spines in, 48. 

 Athyridas, 283. 



brachial supports in, 276. 

 diverging cones in, 283. 

 fleshy portions of brachia in, 283. 

 primary lamellae in, 416. 

 Athyris, 245, 284, 387. 



dorsal beak in, 264. 

 Atops, 129, 139, 140, 141,153. 

 cephalon of, 1 28. 

 characters of, 141. 

 glabella in, 141. 

 trilineatus, 141. 



characters of, 141. 

 Atremata, 242, 244, 245, 247, 267, 282. 



defined, 243. 

 Atretia, 231, 245, 271. 



protegulum in, 234. 

 Atrypa, 245, 284, 395, 416. 

 aspera, 24, 25. 

 disunited loop in, 292. 

 dorsal beak in, 264. 

 hystrix, 24, 25. 



marginal spines of, Hall and 



Clarke, 45. 



reticularis, 24, 25, 315, 327, 350, 

 352. 

 beak in, 389. 



