INDEX 



609 



adult loop in, 291. 

 Jloridana, 297, 300. 

 Grayi, 297. 



adult characters of loop in, 295. 

 ismeniform stage of, 300. 

 muhlfeldtifortn stage in, 301. 

 new genus, 297. 

 Raphaelis, 297. 



adult characters of loop in, 295. 

 septigera, 300, 409. 



adult characters of loop in, 295. 

 brachial supports in, Friele, 



Deslongchamps, 406. 

 development of loop in, Friele, 



Deslongchamps, 292. 

 transformations in, Friele, 298. 

 Dallinime, 295, 302. 



boreal distribution of, 304. 

 denned, 307. 

 median septum in, 296. 

 ontogeny and morphology of, 300. 

 small cardinal processes in, 296. 

 stages of growth in, 288, 303. 

 Dalman, J. W., classification of trilo- 



bites, 111. 

 Dalmanella, 387, 388, 394. 



absence of embryonal sinus in, 388. 

 elegantula, 315, 317, 318, 321, 322, 

 352. 



discussion of, 317. 

 earliest growth-stages in, 373. 

 mature individuals in, 373. 

 Dalmanites, 113, 129, 156, 157, 179. 

 eyes in, 126. 



features of dorsal shield of, 182. 

 free-cheeks in, 117, 124, 181. 

 genal angles in, 123. 

 larvae of, 128. 



nasutus, spinose cephalon in, 157. 

 no eye-line in, 180. 

 ontogeny of, 128, 129, 135. 

 pleura from pygidium in, 127. 

 pygidium in, 181. 

 socialis, 175, 176. 

 tridens, spinose cephalon in, 157. 

 Dana, J. D., principle of cephalization 



in Crustacea, 83. 



Daphnia, absence of median eye in, 

 193. 



nauplius appendages of, 192. 

 Darwin, C., horns in Chamseleontidae, 

 59. 



origin of so called rudimentary or- 

 gans, 80. 



sexual selection as affecting the 

 growth of antlers in the deer, 58. 



spines on shells of barnacles, 52. 

 Davidson, T., casts of pedicles of fossil 

 Lingula3 and Eichwaldia, 257. 



relationsof Bilobiteswifh Orthis,3S9. 



spines in Brachiopoda, 51. 

 Davidsonella, 245. 



schizolophus stage in, 279. 

 Davidsonia, 245, 284. 



hinge in, 236. 



spiral impressions on valves of 276. 

 Daviesiella, 245. 

 Dayia, 245, 413, 416. 



navicula, 413. 

 Decapoda, 200. 



spines on zoe'a of, 46, 57. 



spiny forms of, 70. 

 Dechenella, 148. 



lobation of glabella in, 148. 

 deer, absence of antlers in ancestors of, 



24. 



antlers of, 9, 21. 



development of horns in, 14. 



early, antlers in both sexes of, 57. 



fallow, antler of, 53. 



family, compound antlers in, 68. 



growth in antlers of, 10. 



modern, shedding of antlers of, 97. 



sexual selection as affecting growth 

 of antlers in, Darwin, 58. 



simple antlers of young, 24. 



spine production in, 13. 



Tertiary, simple antlers in, 52. 

 defences, mechanical and motor, in ani- 

 mals and plants, Morris, 97. 

 Deiphon, 153, 155, 156. 



Forbesi, spiniform processes in, 78, 

 79. 



free-cheeks in, 118. 



glabella and pygidium in, 155. 

 Delthyris, 399. 

 delthyrium, 257. 

 deltidial plates, origin of, 257. 

 deltidium amplectens, 391. 



development of, Deslongchamps, 

 Clarke, 263. 



discretum, 391. 



origin of, 257. 



sectans, 391. 



