612 



COMPARATIVE ANATOMY 



Megistocrinus, 307 

 Melampas, 109 

 Melanidce, 6 

 Meleagrina, 17 



,, margaritifera, 17 



Melibe, 13 

 Mdlita, 293 



,, testudinata, 293 

 Melocrinidce, 307 

 Melocrinus, 307 



typus, 307 

 Melonites, 289 



,, multipora, apical system, 340 

 Melonitidce, 289 

 Membrana limitans, 173 

 Meona ventricosa, apical system, 323 

 Meretrix (Gytherea), 18 

 Meridosternal test, 349 

 Mesites, 313; ambulacrum, section, 386 

 Mesollastus, 315 

 Mesodesinatidce, 18 

 Mesoplax, 64 

 Mesorchium, 230 

 Metablastus, 315 

 ' Metacrinus, 313 



angulatus, tegmen calycis, 365 



Murrayi, 311 



Metaplax, 64 

 Metapodium, 106 

 Metrodira, 298 

 Micrsesthetes, 166 

 Micraster, 293 



,, coranguinum, apical system, 324 

 Miller icrinus, 310 

 Milneria, 49 

 Mimaster, 296 

 Mithrodia, 299 

 Mitra, 101 

 Mitridce, 6 

 Modiola, 15 

 Modiolaria, 15 

 Moira, 503 

 Mollusc, hypothetical primitive, 26 



chilensis, 488 

 Molpadiidce, 287 

 Monocyclic base (Grin.), 328 

 Monocydica, 303 

 Monogonopora, 8 

 Monomyaria, 14, 124 ; shell, 64 

 Monopleuridce, 18 



Monotocardia, 5 ; diagram, 31 ; gills, 90 

 Montacuta, 93 

 Muelleria (Moll.), 124 

 Muelleriacea, 124 

 Miietteridce, 124 

 Muileria (Echin.), 285 

 Murex, 101 



trunculus, alimentary canal, 189 

 Muricidte, 6 

 Mutela, 17 

 jHfutelinc', 51 

 My a, I. 



Myacea, 18 

 Myadce, 64 

 Myiidce, 19 

 Myochama, 51 

 Myopsidce, 24 

 Myriotrochus, 288 



Rinkii, 246 



Mytilidce, 15 

 Mytilus edulis, 15 



NACELLA, 108 



Nacreous layer of shell, 57 



Narica, 108 



Naricidce, 107 



Natantia, 10 



Natica Josephina, 107 ; swelling of foot, 



119 



Naticidce, 6 

 Nautiloidecti 22 



Nautilus, 22 ; eye, 169 ; diagram, 37 ; 

 gonad.s, 230 ; nervous system, 

 145, 146 ; pallial complex, 

 82 ; tentacles, 117 



Pompilius, 22 

 Nautilus group, 68 

 Nectria, 296 



Needham's (spermatophoral) pouch, 238 

 Neocrinoidea, 303 

 Neomenia, 3 

 Neomeniidce, 3 

 Neomeniina, 3 

 Nephropneusta, 78 

 Neptunea contraria, 160 

 Neritacea, 4 

 Neritidce, 5 

 Neritince, 5 

 Neritopsidce, 5 

 Notaeum, 10 

 Notarchus, 10 



punctatus, nervous system, 141 

 Notaspidce, 10 

 Notobranchcea, 90 

 Notobranclweidai, 11 

 Nuchal plate, 126 

 NudeoUastidce, 315 

 Nucula, 14 ; ctenidia, 85 



nucleus, 14 

 Nuculidce, 14 

 Nudibranchia, 12 



OCTOPODA, 24 

 Octopodidce, 24 

 Octopus, 24 ; anatomy, 147 ; nervous 



system, 148 

 vulgaris, 25; gonad, female, 231 ; 



male, 239 



Ocular plates (Echinoid.), 321 ; (Ast.) 354 

 Odontoblasts, 183 

 Odontophore, 336 

 Oigopsidce, 24 

 Oligopygus, 293 

 Oliva, 30 



