610 



INDEX 



Derbya, 245. 



Deslongchamps, E., brachial supports 

 in Macandrevia cranium, Dallina septi- 

 gera, and M'uhlfddtia sanguinea, 406. 

 characters of pedicle-openings, 240. 

 classification of Brachiopoda, 290. 

 deltidium in brachiopods, 391. 

 development of the deltidium, 263. 

 of loop in Macandrevia cranium 



and Dallina septigera, 292. 

 platidiform stage in Platidia, 298. 

 desmids, spine growth in, 42, 43. 

 Desmoncus polycanthus, leaf of, 89. 

 development of trilobites, 109. 

 Diaphanometopus, 155. 



pentamerous lobation of glabella in, 



155. 



diatoms, spine growth in, 43. 

 Diccdosia, King, 399. 

 Dicranogmus, 150. 



glabella in, 150. 

 Dicranograptus Nicholsoni, apertural 



spines on, 45. 

 Dicranurus, 113, 151, 152. 

 Dictyocephalites, 140. 

 Dictyondla, absence of embryonal sinus 

 in, 388. 



Capewelli, 336. 

 reticulata, 315, 388. 

 beak in, 388. 

 discussion of, 335. 

 Dictyospongia Conradi, 49, 50. 



prismatica, 50. 



Dictyospongidse, progressive differentia- 

 tion of ornament in, Hall, 49. 

 Dictyothyris, 245, 305, 307. 

 Dielasma, 245, 283, 291, 305, 307, 411, 

 412. 



brachial supports in, 276. 

 Centronella-like loop in, 281. 

 development of brachial supports 



in, 410. 



loop in, 411,413. 

 turgidum, brachidium in, 281. 



development of brachial sup- 

 ports in, 410. 



loop in, 412. 

 Dielasmina, 307. 

 differentiation, specific, in Achatinellse, 



Hyatt and Verrill, 36. 

 Difflugia acuminata, spines on fundus of, 

 43. 



with spine from fundus, 44. 



constricta, spines in, 44. 

 variable form of, 43. 



corona, spines on fundus of, 43. 



globulosa, spherical shell of, 43. 



pyriformis, pear-shaped shell of, 43. 

 Dignomia, 243. 

 Dikelocephalinae, 145. 

 Dikelocephalus, 113, 142, 143, 145. 

 Dimerella, 245. 

 Dindymene, 153. 



glabella in, 154. 



pentamerous head axis in, 154. 



pygidium in, 223. 



spiniform processes in, 78. 

 Dinobulus, 243. 



Dinocerata, no descendants of, 96. 

 dinosaur, Jurassic, suppressed first digit 



in, 85. 



Dinosauria, gigantic Cretaceous, ex- 

 treme spinosity in, 70. 



great horned, protective plates and 



spines in, 54. 

 Diodon, 70. 



maculatus, protective spines in, 55. 

 Dionide, 137, 138, 220. 



determination of sutures in, Bar- 

 rande, 134. 



eye-spots lost in, 135. 

 Dipleura, 129, 154. 



glabella and pygidium in, 155. 

 Discina, 231, 244. 

 Discinidae, 287. 

 Discinisca, 231, 244, 247, 255, 268, 284. 



arms of, 276. 



difference in valves in, 234, 235. 



discoid form of shell in, 287. 



growth of spiral arms in, Muller, 

 282. 



hinge-line lost in, 236. 



larval form of, Muller, 246. 



outline and hinge in, 238. 



pedicle in, 235, 251. 

 -opening in, 241. 



protegulum in, 229, 234. 



recent, discoid form of shell in, 

 287. 



similar form in both valves in, 236. 



stages of development in, 265, 266. 



striata, 236. 



tentacles in, 275. 



of taxolophus in, 277. 



