628 



INDEX 



Heticularia, 246. 



bicostata, var. pelila, 315. 

 development of, 381. 

 discussion of, 380. 

 Retiograptus tentaculatus, apertnral 



spines on, 45. 

 Retzia, 246, 366, 395. 



evax, 360. 

 Rhinoceros, spine production in, 13. 

 Rhipidomella, 245, 387. 



absence of embryonal sinus in, 388. 

 ht/brida, 315, 317, 318, 352. 

 discussion of, 321. 

 earliest growth-stages in, 373. 

 mature individuals in, 373. 

 Ehizopoda, freshwater, Leidy, 43. 

 Rhombopteria, 23. 



Rhopalastrum hexaceros, spines in, 44. 

 hexagonum, 44. 

 malleus, 44. 

 triceros, spines in, 44. 

 Rhi/nchoiiella, 231, 246, 256, 257, 284, 392, 

 395. 



acinus, 339. 

 arms of, 276. 

 arm structure in, 276. 

 brachia in, 279. 

 delthyrium of young, 262. 

 deltidial plates in, 386, 391, 395. 

 development of, 383, 385. 

 dorsal beak in, 264. 

 indianensis, 346. 

 neglecta, 341. 

 pedicle-opening in, 242. 

 spirolophus stage in, 284. 

 tentacles in, 275. 

 Whitii, 344, 366. 

 Rhynchouellae, some Mesozoic, deltidial 

 plates in, 391. 



umbo in ventral valve of, 394. 

 Rhynchonellidse, 271. 



deltidial plates in, 266. 

 deltidium in, 393. 

 shell in, 234. 



some Mesozoic, processes on del- 

 tidial plates of, 390. 

 RhynchoneUina, 246. 

 Rhynchotrema, 246. 

 Rhynchotreia, 246, 387. 



cuneata, 315, 350, 352, 358. 



circular apical perforation in, 

 389. 



deltidial plates in, 390. 

 plications in, 397. 

 profiles of beaks in, 389. 

 sinus and fold in, 388. 

 var. americana, discussion of, 

 351. 

 Rhynchoporina, 246. 

 Rhynobolus, 243. 

 rhythm, Spencer, 28. 

 Robinia Pseudacacia, spiniform stipules 



of, 75, 

 Rcemerella, 244. 



Romanes, G. J., spines caused by sup- 

 pression of an organ, 39. 

 Romingeria, 433. 



corallum in, 433. 

 erect growth in, 427. 

 growth in, 425. 

 periods of gemmation in, 428. 

 rose, loss of spines of, by cultivation, 74. 



prickles on, 9. 

 Rotatoria, spines on loricse of some, 45. 

 Rubus squarrosus, 89. 

 Rudistes, 236. 

 Ruminata, horns in, 58. 

 Ryder, J. A., correlations of volumes 

 aad surface of organisms, 27. 



Sahella, 254. 



Sacculina, absence of intestine in, 193. 

 Salter, J. W., classification of families 

 of trilobites, 110, 112, 132. 



metamorphoses of trilobites, 166. 

 Salteria, 138, 140, 220. 

 Sao, 142, 145, 173, 176, 179, 182. 



eye-line in, 125, 126, 179, 180. 



eyes in, 126, 180. 



first protaspis stage in, 139. 



free-cheeks in, 123, 181. 



glabella in, 180. 



in larval, 126, 141. 



hirsuta, 172, 176. 

 Barrande, 166. 



nepionic, 139, 140. 



ontogeny of, 128, 135. 



pleura from pygidium in, 127. 



protaspis stage in, 136. 



pygidium in, 181. 

 Sarcoptes scabiel, suppression of limbs 

 in, 83. 



