Index to Vo/s. XI -XX. 
Spathularia nigripes, description, xi. 257. 
— rufa, description, xi. 257, 258. 
'var . badipes , description, xi. 258. 
— velutipes, description (*), xi. 256. 
Spaihulea, description, xi. 253. 
— rufa , description, xi. 258. 
Spencerites, a new genus of Lycopodiaceous 
cone from the Coal Measures (+), xi. 590. 
— n.gen ., description (t), xi. 592 ; xix. 278. 
— insignis (t), axis-structure (*), xix. 273 ; 
description, xi. 592 ; xix. 278 ; sporangia 
and sporophylls (*), xix. 276. 
two new specimens of (* t), xix. 273. 
— majusculus, n. sp., description (+), xi. 593. 
Spermatia, nature of (*), xviii. 346. 
Spermatogenesis in Fossombronia longiseta 
(*), xx. 94; Lilium Martagon (*), xi. 
187 ; Nemalion multifidum (*), xviii. 615. 
Spermatozoa of Ferns, chemotaxis, xiv. 543 ; 
physiology, xiv. 543 ; starch in vesicle of, 
xiv. 579 ; swarm period, length in, xiv. 
575 ; withdrawal of water from, xiv. 572. 
Spermatozoid of Chara, development (*), 
xviii. 245 ; of Onoclea (*), xii. 272. 
Spermatozoids of Gymnosperms, xi. 344. 
Spermogonia of Gymnosporangium clava- 
riaeforme (*), xviii. 336 ; of Phragmidium 
violaceum (*), xviii. 335. 
Sphaeriaceae, descriptions of coprophilous 
(*), xv. 334 ; xvi. 71. 
Sphaeria bovilla, an immature stage of S01*- 
daria coprophila, xv. 343. 
— stercoraria, description, xv. 343. 
Sphaeroderma fimbriatum, description (*), 
xv. 351. 
— Hulseboschii, description (*), xv. 352. 
Sphaeronaemella fimicola, description (*), 
xvi. 75. 
Sphaeropsideae, coprophilous, xvi. 75. 
Sphaerotheca, fertilization (*), xix. 567. 
Sphenophyllaceous cone (Sphenophyllum 
fertile) from Lower Coal Measures, new 
type of (t), xix. 168. 
Sphenophyllum fertile, a new type of 
Sphenophyllaceous cone from the Lower 
Coal Measures (+), xix. 168. 
Spindle-formation in pollen-mother-cells of 
Larix: felt, formation of (*), xvii. 292 ; 
pre-radial stages (*), xvii. 289 ; radial 
stages (*), xvii. 291 ; spindle (*), xvii. 295. 
Spinous roots of Dioscoreaprehensilis, mor- 
phology and structure (*), xi. 327 ; xvii. 
420. 
Spiranthes cernua, mycorhiza, xiii. 27 ; root- 
structure, xiii. 27. 
Spirogyra, effect of centrifugal force on cell 
of (*), xiii. 332. 
Sporangia and asci, cell-division in (*), xiii. 
467. 
— in Lycopodium rigidum, abnormal plu- 
rality (*), xvii. 278. 
— of Petrospongium Berkeleyi, plurilocular 
(*), xiii. 461. 
Sporangia of Pteridophytes, imperfect: are 
they vestigial? xv. 225. 
— on Fern prothalli, development, xi. 157, 
xii. 251. 
Sporangial integuments, morphology, xvi. 
596. 
Spore-development in Helminthostachys 
zeylanica (*), xx. 177. 
Spore-distribution of the Uredineae, xix. n. 
Spore-formation in Botrychium virginianum 
(*), xix. 465; Conjugatae (*), xii. 29; 
Leptosporangiate Ferns (*), xviii. 445 ; 
Saccharomycetes (*), xii. 532 ; xv. 759. 
Spore-producing members, studies in the. 
Part III. Marattiaceae, xi. 488 ; Part IV. 
Leptosporangiate Ferns, xiii. 320 ; Part V. 
General comparisons and conclusions, 
xvii. 618, 
Spores of Bacillus hirtus (*), xx. 234; de- 
velopment (*), xx. 250; germination (*), 
xx. 236. 
— of Ophioglossum, germination, xx. 321. 
— of Riccia glauca, development (*), xx. 
275. 
Sporocarp and leaf of Marsilia quadrifolia, 
development (*), xii. 119. 
Sporodesmium piriforme, description (*), 
xvi. 85. 
Sporodinia, cell-division in the sporangium 
(*), xiii - 5 ° 3 - 
Sporophyll-structure of Bowen ia spectabilis 
(*), xii. 219 ; Ceratozamia latifolia, xii. 
232 ; Ceratozamia mexicana (*), xii. 232; 
Ceratozamia Miqueliana, xii. 233 ; Cycas 
circinalis (*), xii. 215 ; Cycas revoluta 
(*), xii. 2 t 1 ; Dioon edule (*), xii. 221 ; 
Encephalartos villosus (*), xii. 223 ; Ma- 
crozamia Fraseri, xii. 224 ; Stangeria 
paradoxa (*), xii. 215 ; Zamia Fischeri, 
xii. 230 ; Zamia furfuracea, xii. 229 ; 
Zamia latifolia, xii. 225; Zamia Lei- 
boldii (*), xii. 230; Zamia Lindeni (*), 
xii. 227; Zamia Loddigesii (*), xii. 228; 
Zamia muricata, xii. 227 ; Zamia pumila, 
xii. 226; Zamia Skinned, xii. 226. 
Sporophylls of Cycadaceae, vascular struc- 
ture (*), xii. 203. 
Sporormia fimetaria, description (*), xv. 347. 
— gigantea , description (*), xv. 346. 
— longipes, n. sp., description (*), xv. 346. 
— ovina, description (*), xv. 346. 
— pulchella, description (*), xv. 347. 
Sporormiella nigropurpurea, description (*), 
xv. 348. 
Sprague, T. A.— On the Heteranthus sec- 
tion of Cuphea (Lythraceae) (Plate XI), 
xvii. 159. 
Spruce, Richard.— Biography (Portrait), 
xiv. xi. 
Spumatoria, n.gen., description, xv. 350. 
— longicollis, n. sp., description (*), xv. 351. 
Stangeria paradoxa ; microsporangia, de- 
velopment and morphology (*), xi. 421; 
