INDEX 



681 



Mantle-groove, formation of, in Paludina, 

 314 



Mantle-layer, definition of, 63 



Manubrium of medusa of Podocoryne, 61 ; 

 of TubtUaria, 58 



Mastax, formation of, in Oallidina russeola, 

 424 



Maturation, divisions of germ-cells, 3 ; of 

 egg, in Crepidida, 7, 8 ; of spermatozoon, 

 in Lepidosiren, 4-6 



Maxillipedes, development of, in larva oiAch- 

 theres amiloplitis, 207 ; in Astacus, 186 ; 

 in Mysis larva of Crangonidae, 215 ; in 

 Gydops, 197 



Mayer's fixative, 35 



Median dorsal arm of ciliated band of larva 

 of Asterias, 464 



Median retractor muscle of larva of Dreis- 

 sensia, formation of, 341 



Median ventral arm of ciliated band of larva 

 % of Asterias, 464 



Medullary folds, formation of, in embryo of 

 Cynthia partita, 619 



Medullary plate, formation of, in embryo of 

 Amphioxus lanceolatus, 691 



Medusa-buds {see Gonophore) of Siphono- 

 phora, 66; of Tubidaria, development of, 57 



Medusae, free, development of eggs of, 59- 

 61 



Medusome tKeory of Haeckel, 66 



Megalopa larva of Brachyura, 216 



Melicertidea, 418 



Mellita testudinata, 504, 522 



Melolontha, 287 ; abdominal appendages of, 

 266 



Membranipora, development of, 387-394 



Membranipora pilosa, 387 



Meridional canals, formation of, in Berbe, 94 



Meroblastic segmentation, definition of, 26 ; 

 in eggs of Arthropoda, 178 ; in eggs of 

 Cephalopoda, 178, 353 ; in eggs of Pera- 

 carida, 193 ; in eggs of Pyrosoma, 632 ; 

 in eggs of Scorpion, 240 ; in eggs of Sepia, 

 353 



Mesectoderm in Annelida, MoUusca, and 

 Gephyrea, 401 ; formation of, in Lepas, 

 195 ; in MoUusca, 323 ; in Patella, 309 ; 

 in PhascolosoriM, 376 ; in Planocera, 111 ; 

 in Polygordius, 135 



Mesenchyme, definition of, 120 ; formation 

 of, in embryo of Antedon rosacea, 545 ; 

 in larva of Asterias, 461 ; in larva of 

 Balanoglossus clavigerus, 573 ; in larva of 

 Cerebratulus lacteus, 120 ; in larva of Ou- 

 cumaria planci, 542 ; in larva of Oynthia 

 partita, 614 ; of Grantia, 39 ; in larva 

 of Holothuria tiibulosa, 541 ; in larva 

 of Ophiura brevispina, 501 ; in larva of 

 Pedicellina echinata, 401 ; in embryo of 

 Pyrosoma, 635 ; in larva of Synapta 

 digitata, 531 



Mesendoderm, formation of, in Orepidula, 

 323 ; in Dreissensia, 335 ; in Fiona, 323 ; 

 in Physa, 323 ; in Sepia, 356 



Mesenteric stomata of Urticina crassicornis, 

 80 



Mesenterial filaments of Urticina crassicornis, 

 81 



Mesentery of Urticina crassicornis, 79 



Mesoderm, formation of, in Agelena, 224 ; 

 in Alcyonidium albidum, 388; raAmpM- 

 oxus lanceolatus, 592; in Astacus, 180; 

 in Beroe, 93 ; in Blatta, 261 ; in Crepidula, 

 322 ; in Donacia, 248 ; in Dreissensia, 

 335 ; in Euphausia, 192 ; in Fiona, 322 ; 

 in Lepas, 195 ; in Limulus, 236 ; in 

 Nephelis, 161 ; in Oligochaeta, 156 ; in 

 Pallene, 243 ; in Paludina, 310 ; in 

 Patella, 295 ; in Pedicellina, 399 ; in 

 Pedipalpi, 241 ; in Phascolosoma, 376 ; 

 in Physa, 322 ; in Planocera, 108 ; in 

 Polygordius, 143 ; in Polyphemus, 194 ; 

 in Salpa, 636 ; in Scorpion, 240 



Mesodermal bands, formation of, in Agelena, 

 225 ; in Dentalium, 329 ; in Lepas, 195 ; 

 in Lepisma, 265 ; in Oligochaeta, 156 ; in 

 Pcduditia, 310 ; in Patella, 299 ; in 

 Pedicellina, echinata, 401 ; in I'eripatus 

 capensis, 171 ; in Polygordius, 138 ; in 

 Polygordius appendiculatus, 144 ; in 

 Scolopendra, 283 



Mesogloea of Urticina ci-assicornis, 79 



Mesomeres in egg of Echinus esculentus, 506 



Mesonemertini, 118 



Mesotrochal larva, definition of, 153 



MetamorphosisofCopepodidlarvaofylcAyiCj'es 

 ambloplitis, 207, 208 ; of larVa of Amphi- 

 oxus lanceolatus, 603, 604 ; of larva of 

 simple Ascidian, 622 ; of larva of As- 

 terias, 467-472 ; of the larva of Asterina 

 gibbosa, 474-479 ; of Zoaea larva of 

 Brachyura, 216 ; of larva of Giona intesti- 

 nalis, 622-628 ; of pupa of Cirripedia, 

 202 ; of Mysis larva of Crangonidae, 21 5 ; 

 of larva of Cyclops, 198, 199 ; of larva of 

 Dreissensia, 343 ; of larva of Echinus 

 esculentus, 612-518 ; of Insects, 266-280 ; 

 of larva of Membranipora, 394 ; of larva 

 of Ophiothrix fragilis, 492-498 ; of larva 

 of Ostracoda, 203 ; of larva of Pedicellina 

 echinata, 402, 403 ; of larva of Phascolo- 

 soma, 377, 378 ; of larva of Phoronis 

 (Actinotrocha), 383, 384 ; of larva of 

 Polygordius appendiculatus, 149-151 ; of 

 larva of Synapta digitata, 636-541 ; of 

 larva of Terebratidina septentrionalis, 412, 

 413 ; of New England Tornaria larva, 

 577-579 ; of Nassau Tornaria larva, 580, 

 581 ; of the larva of Yungia (Pilidium), 

 112-115 



Metanauplius larva of Cyclops, 198 ; of 

 Stomatopoda, 216 



Metanauplius stage in development of 

 Achtheres ambloptitis, 206 



Metanemertini, 118 



Metanephridia, formation of, in Polygordius, 

 147 



Metasyndesis, definition of, 12 



