Chaetopterus,304n.,323;anatomy,323f.;special chaetae,267;larva,274,325;pigment,292;phosphorescence,295,296;commensals of,298,478,533;Ch. variopedatus,324Chaetosoma,158Chaetosomatidae,158Chaetosyllis, form of head,278Chaetozone,326;uncini,268Chaetura,235Chalk, Serpulids of,301Charles, on male guinea-worm,148Cheilostomata,477,506,518,519,525,526f.;occurrence,478;external characters (see also Avicularium and Vibraculum),481;ovicells,507;reproduction,507f.;larva,511;fossil,521Chiaje, Delle, on Gephyrea,411Chickoff, on Triclads,41Chironomus, host ofGordius,172Chitin,249,267;in coelomic corpuscles,252Chloeia, colour,291Chlorhaemidae,258,305,334,336;chlorocruorin in,252;head,260,262,264;palps,260;tentacles,262Chlorocruorin,252,334;colour due to,291Chone,338Chorizopora,530Cilia,3;ofLeptoplana,10,11,12,15;of Polyclads,23,25,26;of Müller's larva,29;of Land Planarians,33;ofPlanaria lactea,35;ofTemnocephala,53;of Trematode-larvae,3,59,60,65;of Cestode-larvae,87;absent in certain groups,124,396;of Rotifers,202f.;of Archiannelida,243,244;of Echiuroidea,434;ofPhoronis,453;of Polyzoa,467,470Ciliated, lappets, ofPterosyllis,273n.;pits, ofPolygordius,244;pits (= nuchal organs), of Polychaeta,272f.;organs, of Capitelliformia,305Cingulum, in Rotifers,202Cirratulidae,258,325;gill,265;tentacular filaments,304n.Cirratulus,326;burrows,286;pigment,292;colour,293;viviparous,276;C. tentaculatus,326Cirri, ofNereis,246;of Polychaeta,265;ofMyzostoma,342;anal,259;nuchal, of Eunicidae,318;peristomial, ofNereis,248;nerves to,254;of Polychaeta,263Cladocora, withMyxicola,294Claparède, on Heteronereis,276,277;on Earthworms,347,355,356Claus, on Nematoda,138;on Seisonaceae,225n.Clepsine—seeGlossiphoniaClitellio,366,378Cloeosiphon,424,425,429Clover sickness,155Clymene,333;C. ebiensis, tube of,287Clymenidae—see MaldanidaeCoabangia,284,339n.Cobb, on Nematoda,131n.,138Cobbold, on Nematoda,140Cobitis, host ofGordius,173Cochleare,225Cocoons, of Triclads,40;of Oligochaeta,364,365;of Leeches,404Coelom—see Body-cavityCoelomic fluid, of Polychaeta,252;as cause of colour,291Coelopus,225Cohn, on Rotifers,198Collar, peristomial, of Sabellidae,336;of Gephyrea,421;of Ctenostomata,470,477,480,481Colonial nervous system,471Colony, ofMyrianida,281;ofSyllis ramosa,282;of Polyzoa,466Colour of Polyclads,20;of Land Planarians,33;of Nemertinea,102;of Polychaeta,291,314,340Coluridae,207,225Colurus,225,226Comatula, as host,342Commensal, Polychaeta,297f.,323,325;Gephyrea,428,429;Polyzoa,489Conn, on development of Gephyrea,419n.,441,444,447Conoceros,19Conochilus,202,203,205,215,221,226Conocyema, hosts of,94Convoluta,45;British species,43,49;C. henseni, pelagic habit,43;C. roscoffensis, assimilating tissue,43Copepoda, on Polychaeta,299Copeus,215,224Coral reefs, Polychaeta in,293Corallina(= Coralline Alga),14,488,516Coralline,465Coralline Crag,465,521Corallobothrium,91Corethra, host ofGordius,172Cori, onPhoronis,451f.Cornulites,302Cotylea,16f.,17,18Cotylogaster,73Cotyloplana,35Crateromorpha, as host,282Crayfish,Temnocephalaassociated with,53Creeper,317Crepina,450Cretaceous, Polyzoa,520,521Cribrilina,518,524,528Crinoids, as hosts,341Criodrilus,358,366,386Crisia,471,478,479,480,507,518,531Crisiidae,517Crisp, on Parasites,164Cristatella,494f.,495,499,501,503-505,512,518;attacked by Planarians,486;movements,494,496,498;fission,496,506;statoblast,502,503;larva,512Crossopodia,302Crotchets,266,267,305,322Crustacea, parasites of,174,179,182Cryptocelis,19,24Cryptocephala,258,303,305;vascular system,252;prostomium,259;tentacles,263;eyes,272;food,296Cryptodrilidae,357,362,373,382Cryptodrilus,372,382f.Ctenodrilus,373Ctenophores, as hosts,298Ctenostomata,470,477,479,480,518,532;occurrence,478;in fresh water,492;external characters,480;reproduction,507;larva,511;relation to Phylactolaemata,493,502f.;fossil,521n.Cucullanus,136,142,163;C. elegans,143,161Cucumaria, as host,298Cuénot, on Gephyrea,416n.Cuticle, of Nemathelminthes,125,165,175;of Rotifera, etc.,205,233,236;of Polyzoa,470—see also EpidermisCuvier, on Oligochaeta,352;on Gephyrea,411Cyclatella,489Cyclicobdella,392Cycloporus,19,22,24Cyclops, parasites of,143,148,161Cyclorhagae,238Cyclostomata,477,479,506,517,518,525,531;occurrence,478;external characters,480;ovicells,507;reproduction,507,511;larva,511; fossil,520,521Cydippe, as host,298Cylindroecium,533Cylindrostoma,46;British species,50Cyphonautes,509,510,512,520Cyprina,Malacobdellafound on,119Cyrtonia,224Cyst, of Land-Planarians,33;ofMyzostoma,342,343,344;(capsules), ofAeolosoma,370,375Cystibranchus,395,406Cysticercoid-larva,83,85,88Cysticercus-larva,79,80;list of,83;C. cellulosae,79,80;C. pisiformis, development,81,85,89Cysticolous, Myzostomaria,344Cystoidotaeninae,91Cystotaeninae,91Dactylogyrus,73Dalyell, on habits of Turbellaria,6,10,20;on regeneration in Polychaeta,283;on tubes of Polychaeta,287;on Hirudinea,405n.;on larvae ofFlustra,466;onCristatella,496Danielssen and Koren, on Gephyrea,442,444Daphnia, Rotifers attached to,227Dapidia,225Darwin, on Earthworms,354,359,368Dasybranchus,331;gill,268Dasychone,338;gills,261;eyes,272;regeneration,283Dasydetes,232,235Davaine, on Nematoda,140,145Davainea,91;D. friedbergeri,84;D. madagascariensis,80,84;D. proglottina, life-history,84Davenport, onUrnatella,491Davis, on Rotifers,227Deep-sea, Polychaeta,300;Polyzoa,478Deinodrilus,351,384Delagia,478n.Dendrobaena,382Dendrocoelum,30,35,39Dendrostoma,422,425,428Dendy, on Land Planarians,33,34,38Denticles,248,250,316,522Dero,352,377Derostoma,44,50Desmogaster,380Desmoscolecidae,159Desmoscolex,159,258Desor, on Nemertine development,99;Type of, larva,113Development, of Polyclads,28;of Nemertinea,99,113;of Nematoda,135;ofGordius,171;of Acanthocephala,179;of Chaetognatha,189;of Rotifers,218;of Archiannelida,243,245;of Polychaeta,274f.;of Oligochaeta,365;of Leeches,399;of Gephyrea,419,432,439,447;ofPhoronis,458;of Polyzoa,506,509—see also Life-history and LarvaDiachaeta,366Diaphragm, ofNereisintrovert,250,251;of Terebellidae,304,327;of Polyzoa,469,470,500,508Diaschiza,225,226Diastopora,518,531Dichogaster,362,383Diclidophora,73Dicotylus,32,35,36,42Dicranotaenia,91;D. coronula, life-history,84Dicyema,93;vermiform larva of,92;hosts of,94Dicyemennea,93,93;hosts of,94Dicyemidae,92f.Didymogaster,383Didymozoon,73;D. thynni(=Monostomum bipartitum),71Didymozoontidae,73Digaster,358,359,382f.Digenea (Digenetic Trematodes),5,52,62,73;occurrence and habits,62;life-histories,63f.,71f.Digestive system, ofLeptoplana,11,12;of Polyclads,24;of Triclads,37,39;of Rhabdocoelida,42f.;ofTemnocephala,53,54;ofPolystomum,57;ofDistomum,62;absence of, in Cestodes,74;of Nemertinea,103,103,104;
Chaetopterus,304n.,323;
anatomy,323f.;
special chaetae,267;
larva,274,325;
pigment,292;
phosphorescence,295,296;
commensals of,298,478,533;
Ch. variopedatus,324
Chaetosoma,158
Chaetosomatidae,158
Chaetosyllis, form of head,278
Chaetozone,326;
uncini,268
Chaetura,235
Chalk, Serpulids of,301
Charles, on male guinea-worm,148
Cheilostomata,477,506,518,519,525,526f.;
occurrence,478;
external characters (see also Avicularium and Vibraculum),481;
ovicells,507;
reproduction,507f.;
larva,511;
fossil,521
Chiaje, Delle, on Gephyrea,411
Chickoff, on Triclads,41
Chironomus, host ofGordius,172
Chitin,249,267;
in coelomic corpuscles,252
Chloeia, colour,291
Chlorhaemidae,258,305,334,336;
chlorocruorin in,252;
head,260,262,264;
palps,260;
tentacles,262
Chlorocruorin,252,334;
colour due to,291
Chone,338
Chorizopora,530
Cilia,3;
ofLeptoplana,10,11,12,15;
of Polyclads,23,25,26;
of Müller's larva,29;
of Land Planarians,33;
ofPlanaria lactea,35;
ofTemnocephala,53;
of Trematode-larvae,3,59,60,65;
of Cestode-larvae,87;
absent in certain groups,124,396;
of Rotifers,202f.;
of Archiannelida,243,244;
of Echiuroidea,434;
ofPhoronis,453;
of Polyzoa,467,470
Ciliated, lappets, ofPterosyllis,273n.;
pits, ofPolygordius,244;
pits (= nuchal organs), of Polychaeta,272f.;
organs, of Capitelliformia,305
Cingulum, in Rotifers,202
Cirratulidae,258,325;
gill,265;
tentacular filaments,304n.
Cirratulus,326;
burrows,286;
pigment,292;
colour,293;
viviparous,276;
C. tentaculatus,326
Cirri, ofNereis,246;
of Polychaeta,265;
ofMyzostoma,342;
anal,259;
nuchal, of Eunicidae,318;
peristomial, ofNereis,248;
nerves to,254;
of Polychaeta,263
Cladocora, withMyxicola,294
Claparède, on Heteronereis,276,277;
on Earthworms,347,355,356
Claus, on Nematoda,138;
on Seisonaceae,225n.
Clepsine—seeGlossiphonia
Clitellio,366,378
Cloeosiphon,424,425,429
Clover sickness,155
Clymene,333;
C. ebiensis, tube of,287
Clymenidae—see Maldanidae
Coabangia,284,339n.
Cobb, on Nematoda,131n.,138
Cobbold, on Nematoda,140
Cobitis, host ofGordius,173
Cochleare,225
Cocoons, of Triclads,40;
of Oligochaeta,364,365;
of Leeches,404
Coelom—see Body-cavity
Coelomic fluid, of Polychaeta,252;
as cause of colour,291
Coelopus,225
Cohn, on Rotifers,198
Collar, peristomial, of Sabellidae,336;
of Gephyrea,421;
of Ctenostomata,470,477,480,481
Colonial nervous system,471
Colony, ofMyrianida,281;
ofSyllis ramosa,282;
of Polyzoa,466
Colour of Polyclads,20;
of Land Planarians,33;
of Nemertinea,102;
of Polychaeta,291,314,340
Coluridae,207,225
Colurus,225,226
Comatula, as host,342
Commensal, Polychaeta,297f.,323,325;
Gephyrea,428,429;
Polyzoa,489
Conn, on development of Gephyrea,419n.,441,444,447
Conoceros,19
Conochilus,202,203,205,215,221,226
Conocyema, hosts of,94
Convoluta,45;
British species,43,49;
C. henseni, pelagic habit,43;
C. roscoffensis, assimilating tissue,43
Copepoda, on Polychaeta,299
Copeus,215,224
Coral reefs, Polychaeta in,293
Corallina(= Coralline Alga),14,488,516
Coralline,465
Coralline Crag,465,521
Corallobothrium,91
Corethra, host ofGordius,172
Cori, onPhoronis,451f.
Cornulites,302
Cotylea,16f.,17,18
Cotylogaster,73
Cotyloplana,35
Crateromorpha, as host,282
Crayfish,Temnocephalaassociated with,53
Creeper,317
Crepina,450
Cretaceous, Polyzoa,520,521
Cribrilina,518,524,528
Crinoids, as hosts,341
Criodrilus,358,366,386
Crisia,471,478,479,480,507,518,531
Crisiidae,517
Crisp, on Parasites,164
Cristatella,494f.,495,499,501,503-505,512,518;
attacked by Planarians,486;
movements,494,496,498;
fission,496,506;
statoblast,502,503;
larva,512
Crossopodia,302
Crotchets,266,267,305,322
Crustacea, parasites of,174,179,182
Cryptocelis,19,24
Cryptocephala,258,303,305;
vascular system,252;
prostomium,259;
tentacles,263;
eyes,272;
food,296
Cryptodrilidae,357,362,373,382
Cryptodrilus,372,382f.
Ctenodrilus,373
Ctenophores, as hosts,298
Ctenostomata,470,477,479,480,518,532;
occurrence,478;
in fresh water,492;
external characters,480;
reproduction,507;
larva,511;
relation to Phylactolaemata,493,502f.;
fossil,521n.
Cucullanus,136,142,163;
C. elegans,143,161
Cucumaria, as host,298
Cuénot, on Gephyrea,416n.
Cuticle, of Nemathelminthes,125,165,175;
of Rotifera, etc.,205,233,236;
of Polyzoa,470—see also Epidermis
Cuvier, on Oligochaeta,352;
on Gephyrea,411
Cyclatella,489
Cyclicobdella,392
Cycloporus,19,22,24
Cyclops, parasites of,143,148,161
Cyclorhagae,238
Cyclostomata,477,479,506,517,518,525,531;
occurrence,478;
external characters,480;
ovicells,507;
reproduction,507,511;
larva,511; fossil,520,521
Cydippe, as host,298
Cylindroecium,533
Cylindrostoma,46;
British species,50
Cyphonautes,509,510,512,520
Cyprina,Malacobdellafound on,119
Cyrtonia,224
Cyst, of Land-Planarians,33;
ofMyzostoma,342,343,344;
(capsules), ofAeolosoma,370,375
Cystibranchus,395,406
Cysticercoid-larva,83,85,88
Cysticercus-larva,79,80;
list of,83;
C. cellulosae,79,80;
C. pisiformis, development,81,85,89
Cysticolous, Myzostomaria,344
Cystoidotaeninae,91
Cystotaeninae,91
Dactylogyrus,73
Dalyell, on habits of Turbellaria,6,10,20;
on regeneration in Polychaeta,283;
on tubes of Polychaeta,287;
on Hirudinea,405n.;
on larvae ofFlustra,466;
onCristatella,496
Danielssen and Koren, on Gephyrea,442,444
Daphnia, Rotifers attached to,227
Dapidia,225
Darwin, on Earthworms,354,359,368
Dasybranchus,331;
gill,268
Dasychone,338;
gills,261;
eyes,272;
regeneration,283
Dasydetes,232,235
Davaine, on Nematoda,140,145
Davainea,91;
D. friedbergeri,84;
D. madagascariensis,80,84;
D. proglottina, life-history,84
Davenport, onUrnatella,491
Davis, on Rotifers,227
Deep-sea, Polychaeta,300;
Polyzoa,478
Deinodrilus,351,384
Delagia,478n.
Dendrobaena,382
Dendrocoelum,30,35,39
Dendrostoma,422,425,428
Dendy, on Land Planarians,33,34,38
Denticles,248,250,316,522
Dero,352,377
Derostoma,44,50
Desmogaster,380
Desmoscolecidae,159
Desmoscolex,159,258
Desor, on Nemertine development,99;
Type of, larva,113
Development, of Polyclads,28;
of Nemertinea,99,113;
of Nematoda,135;
ofGordius,171;
of Acanthocephala,179;
of Chaetognatha,189;
of Rotifers,218;
of Archiannelida,243,245;
of Polychaeta,274f.;
of Oligochaeta,365;
of Leeches,399;
of Gephyrea,419,432,439,447;
ofPhoronis,458;
of Polyzoa,506,509—see also Life-history and Larva
Diachaeta,366
Diaphragm, ofNereisintrovert,250,251;
of Terebellidae,304,327;
of Polyzoa,469,470,500,508
Diaschiza,225,226
Diastopora,518,531
Dichogaster,362,383
Diclidophora,73
Dicotylus,32,35,36,42
Dicranotaenia,91;
D. coronula, life-history,84
Dicyema,93;
vermiform larva of,92;
hosts of,94
Dicyemennea,93,93;
hosts of,94
Dicyemidae,92f.
Didymogaster,383
Didymozoon,73;
D. thynni(=Monostomum bipartitum),71
Didymozoontidae,73
Digaster,358,359,382f.
Digenea (Digenetic Trematodes),5,52,62,73;
occurrence and habits,62;
life-histories,63f.,71f.
Digestive system, ofLeptoplana,11,12;
of Polyclads,24;
of Triclads,37,39;
of Rhabdocoelida,42f.;
ofTemnocephala,53,54;
ofPolystomum,57;
ofDistomum,62;
absence of, in Cestodes,74;
of Nemertinea,103,103,104;