INDEX 



Helix, 748, 749 



Helix nevwralis, 748 



Hemipneustes radiatus, 423 



Hemiptera, 633*, 638, 653 



Hemisomea, 43* 



Hepatic caeca, 407 



Hepato-pancreas, 34, 549 



Hermaphrodite, 39* 



Hermit-crabs, 569, 588, 589 



Hermit-crabs and Hydractinia, 144 



Herpobdella, 516, 619, 520, 522 



HerpobdelUda, 516* 



Hesionida, 475 



HeterocoBla, 112* 



Heteroootylea— See Monogenetioa, 252 



Heterocyemidce, 230, 232 



Heterogamy, 41* 



Heterogeny, 277*, 287, 310* 



Heteromita, 71, 72, 75, 76 



Heteromyaria, 698* 



Heteronemertini, 296* 



Heteronereis, 440, 450 



Heteropoda, 733*, 738. 740, 756 



Heterotrichous, 92*, 94 



Hexacanth embryo, o£ Tain w , 250 : 

 Cestodes, 280 



Hexactinellida, 112*, 120, 123, 126 



Hexactinice, 196, 200 



Hexarthra, 328, 330, 332, 335 



Hinge-ligament, 682 



Hinge-line, 361, 682 



Hinge-teeth, 361, 683 



Hippa, 569, 589, 603 



Hippurites, 700, 701 



Hlrudinea, 439, 506 : Example, 506 : 

 Distinctive characters and classifica- 

 tion, 515 : General organisation, 517 : 

 Form and size, 517 : Setae, 518 : Pro- 

 boscis, 518 : Enteric canal, 518 : Blood- 

 vessels, 518 : Respiratory organs, 519 : 

 Nephridia, 519, 520 : Nervous system, 

 520 : Sense-organs, 520 : Reproductive 

 organs, 520 : Development, 520, 521 : 

 Habits, distribution, &c., 522, 524 



Hirudinidce, 517* 



Hirudo, 520, 522 



Hirudo atwtralis, 506, 510, 611 



Hirudo medicinalis, 506 : External 

 characters, 506, 507 : Body-wall, 508, 

 Muscular system, 508, 509 : Alimentary 

 organs, 509, 610 : Excretory system, 

 510, 511, 512 : Vascular system, 512, 

 513 : Nervous system, 513 : Sense- 

 organs, 514 : Reproductive organs, 

 514 : Development,, 515 : Systematic 

 position, 517 



HiKUDO QUINQUESTKIATA— See H. MEDI- 

 CINALIS 

 Hirudo sanguisuga, 522 

 Histology, 3* 



Hislriobdellea, 336, 338, 339, 524 

 Holarctic, 9* 

 Holoblastic, 23* 



Holophytic, 65*. 69, 72, 78 



Holothuria— See Sea-cucumber 



Holothurian — See Colochirus 



HolothuToidea : Example, 401 : Distinc- 

 tiA'e characters and classification, 412 : 

 General form, 416 : Modifications of 

 form, 423 : Coelome, 425 : Ambulacral 

 system of vessels, 426 : Blood-vascular 

 system, 426 : Haemal system, 427 ; 

 Axial organ, 428 : Enteric canal, 428 : 

 Respiratory trees, 428 : Guvierian 

 organs, 428 : Nervous system, 429 : 

 Reproductive organs. 429 : Develop- 

 ment, 430 : Ethology, 434 



Holotrichous, 89, 92*, 94 



Holozoic, 65*, 69 



Homcdogaster, 257 



Honiarus, 569, 599 



HomoCcBla, 112* 



Hood, 779* 



Hook-headed worms, 297 



Hoplocarida, 569* 



HoEMiPHORA PLUMOSA, 211 : External 

 characters, 211, 212: Enteric system, 

 213, 214: Cell-layers, 215: Nervous 

 system, 216 : Sense-organs, 216 : Re- 

 productive organs, 216 : Development, 

 217, 218, 219, 220 : Systematic posi- 

 tion, 221 



Host, of parasite, 84 : intermediate, 87 



House-flies, 619, 635 



Hyaline cartilage, 26*, 27 



Hyalonema, 120, 127 



Hyaloaphenia, 49 



Hybrids, 2* 



Hydatids, 282* 



Hydatina, 328, 331 



Hydra, 133, 147, 148, 153, 167, 168 



Hydractinia, 144, 145, 149, 167 



Hydranths, of Ohelia, 129*, 148, 187 



Hydrocoele, 390 



Hydrocorallina, 142*, 156, 157, 158, 159, 

 167 



HydrocorallinsB, distribution, 159 



Hydroctena, 227 



Hydroids, naked-budded, 143* : covered- 

 budded, 143* 



Hydrophilus, 650 



Hydrophyllia, of Halistemnia, 160*, 160 



Hydrorhiza, 128* 



Hydrospires, 414* 



Hydrotheca, of Obelia, 129*, 130, 167 



Hydrozoa, 128 : Example, 128 : General 

 structure and classification, 140: Alter- 

 nation of generations, 141 : System- 

 atic position of example, 142 : General 

 remarks on, 167 



Hydnda, 139*, 140, 153, 229 



Hymenoptera, 636*, 638, 642, 646, 649, 

 653 



Hyperia, 568 



Hypoblast, 23* 



Hypodermic impregnation, 334, 520 



