682 



INYEETEBRATA 



Metatroch of larva of Dreissensia, 340 ; of 

 larva of Phased 'osoma, 376 ; of Actino- 

 troeha larva of Phoronis, 381 ; of larva of 

 Polygordius, 140, 144 ; of adult Polyzoa 

 Ectoprocta, 386 



Metazoa, 51, 100, 170 ; ancestry of, 116, 660 



Metazoaea larva, 213 



Method of finding eggs of Dolichoglossus 

 kowalevskii, 582 



Methods of reconstructing sections, 319 



Mctridium marginatum, 85 



Micromeres in segmenting egg of A mphioxus 

 lanceolatus, 588 ; in segmenting egg of 

 Beroe, 90 ; in segmenting egg of Dentalium, 

 327, 328 ; in segmenting egg of Dreissensia, 

 333, 334 ; in segmenting egg of Echinus 

 esculentus, 506 ; in segmenting egg of 

 Patella, 293-295 ; in segmenting egg of 

 Phascolosoma, 373, 374 ; in segmenting 

 egg of Planocera, 104 



Mid-gut, formation of, in Agelena, 230 ; in 

 Astacus, 189 ; in Donacia, 254 ; inJulus, 

 284 ; in Loligo, 358 ; in Scolopendra, 284 ; 

 metamorphosis of, in larva of Galerucella 

 ulmi, 269 



Middle piece of Spermatozoon, definition of. 7 



Miguel's solution, 131 



Millipedes, 281 



Mites, 242 



Mitrocoma, experiments on eggs of, 96 



Molgula, 628 



Molgida ampulloides, development of, 632 



Mollusca, 105, 108, 157, 372, 400, 401, 405, 

 406, 408, 413, 416, 427, 435, 436, 457, 

 523, 529, 561, 562, 651, 655, 659, 661 ; 

 development of, 291-371 ; development of 

 unfertilized eggs, 17 ; eggs of, 9 ; fossil 

 representatives of, 20 ; sperm of, used to 

 cross-fertilize eggs of Sea-urchin, 17 



Molluscan cross, definition of, 133 ; in seg- 

 menting egg of Crepidula, 322 ; in seg- 

 menting egg of Patella, 294 ; in segment- 

 ing egg of Phaseolosoma, 374 ; in segment- 

 ing egg of Polygordius, 133 



Molluscoida, 608 



Monotrochal larva, definition of, 153 



Monotus, 115 



Monovalens race of Ascaris megalocephala, 

 439 



Morula of Tubularia, 54, 55 



Mouth, formation of, in Amphioxus lanceo- 

 latus, 596 ; in simple Ascidian, 619 ; in 

 Astacus, 183, 184 ; in larva of Asterias, 

 461 ; in adult Asterias, 471 ; in adult 

 Asterina gibbosa, 479 ; in adult Echinus 

 esculentus, 518, 519 ; in adult Ophiothrix 

 fragilis, 495 ; in Paludina, 310 ; in Peri- 

 patus capensis, 171; in Tubularia, 56; 

 function of, in Platyhelminthes, 102 



Mouth in Aurelia identical with blastopore. 

 68 



Miiller's fluid, composition of, use of, 33 



Mu'ller's larva, 104, 164 ; compared to a 

 Ctenophore, 115 



Miiller's papillae, formation of, in larva of 

 Amphioxus lanceolatus, 604 



Musca, 280 



Muscidae, 272, 278, 287 ; metamorphosis 

 of, 278-280 



Muscles, formation of, in Antedon rosacea, 

 558 ; in Callidina msseola, 426 ; in 

 Pilidium larva of Cerebratulus lacteus, 

 120, 121 ; in Cyphonautes larva, 390, 391 ; 

 in arms of Ophiothrix fragilis, 498 ; in 

 stomodaeum of Planocera, 111 ; in blasto- 

 zooid of Urochorda, 639 ; in Urticina 

 crassicornis, 83 ; metamorphosis of, in 

 larva of Galerucella ulmi, 270 



Myoblasts of Nephelis, 162; of Criodrilus, 

 158 



Myocoeles in Amphioxus lanceolatus, 601 



Myotomes, formation of, in Amphioxus 

 lanceolatus, 595 



Myriapoda, 169, 177, 245, 285; development 

 of, 280-284 



Mysidacea, 177, 219 



Mysis, 193 



Mysis larva, 213, 217 ; interpretation of, 

 213 ; of Astacidae, 213 ; of Crangonidae, 

 215 ; of Loricata, 214 ; of Thalassiuidae, 

 215 



Mytilus, 332, 523 



Narcomedusae, 53 ; development of, 66, 67 



Nauplius larva, 285, 654, 655 ; interpreta- 

 tion of, 204, 205 ; of Apus, 201 ; of 

 Branchiopoda, 201 ; of Cirripedia, 201 ; 

 of Cladocera, 200 ; of Cyclops, 196-197 ; 

 of Euphausidacea, 203 ; of Ostracoda, 

 203 ; of Penaeidea, 203 ; of Penaeus, 22, 

 of Sacculina, 202; of Stomatopoda, 217 



Nauplius - like ancestor of Crustacea, 205, 

 212 



Nauplius stage in development of Achtheres 

 ambloplitis, 206 ; of Astacus, 185 



Nautilus, 358 ; motion of, 369 



Neanic stage of development, 1 9, 22 



Nectocalyx of Siphonophora, 64, 66 



Nematoda, 436, 457 ; development of, 437- 

 455 



Nemertinea, 157, 164, 166, 167, 457, 529, 

 561, 600, 661 ; development of, 118-127 



Nephridia, formation of, in Amphioxus 

 lanceolatus, 600 ; in Criodrilus lacuum, 

 158 ; in Nephelis, 162 ; in Phascolosoma, 

 379, 380 ; in Actinotrocha larva of Phor- 

 onis, 381, 382 ; nature of, in Annelida, 

 157 



Nephridioblasts of Nephelis, 162 



Nephrops, 213 



Nephropsidea, 177 



Nephrostome, formation of, in Phascolosoma, 

 380 



Nereidiformia, 128, 153 



Nereis, 129, 153, 156, 321, 333, 645; 

 development of, 155, 156 



Nerve-collar of Polygordius appendiculatvs, 

 formation of, 147 



