14 Contents 



CHAPTER 23 Page 



THE PHYLUM NEMATHELMINTHES AND RELATED PHYLA ...423 

 Characteristics of the Phylum, 424; The Classification of the Nema- 

 thelminthes, 426 ; The Class Nematoda, 426 ; The Anatomy of Chilo- 

 placus, 427; The Biology of the Free-Living Nematodes, 429; The Plant 

 Nematodes, 429; The Nematodes Parasitic in Animals, 430; Life Histories 

 of Some Important Nematode Parasites, 430; Ascaris, 430; The Hook- 

 worms, 432; The Trichina Worm, 434; The Pinworm, 435; The Whip- 

 worm, 435 ; Elephantiasis, 436 ; Onchocerciasis, 437 ; The African Eye- 

 worm, 437 ; Dracunculus, 437 ; Minor Phyla Related to the Nematodes, 

 438 ; The Phylum Rotifera, 438 ; The Phylum Gastrotricha, 441 ; The Phy- 

 lum Kinorhyncha, 441 ; The Phylum Nematomorpha, 442 ; Pseudocoelo- 

 mate Phyla of More Distant Relationship to the Nematodes, 443 ; The Phy- 

 lum Acanthocephala, 443; The Phylum Entoprocta, 445; The Phylum 

 Priapulida, 445. 



CHAPTER 24 



THE PHYLUM ANNELIDA AND OTHER WORMLIKE 



COELOMATES 446 



The Characteristics of the Phylum, 446; The Classes of Annelida, 449; 

 Class Archiannelida, 450; Polygordius, 450; The Class Polychaeta, 450; 

 The Anatomy of Neanthes, 450; The Trochophore Larva, 452; The Bi- 

 ology of Neanthes, 453 ; Other Polychaetes, 453 ; The Class Oligochaeta, 

 454 ; The Anatomy of Lumbricus terrestris, 455 ; Mating Behavior of L. 

 terrestris, 459; The Biology of L. terrestris, 460; Other Oligochaetes, 

 461 ; The Class Hirudinea, 462 ; Other Eucoelomates Related to the An- 

 nelida, 463 ; The Phylum Echiuroidea, 463 ; The Phylum Sipunculoidea, 465. 



CHAPTER 25 



THE PHYLUM MOLLUSCA AND SOME MINOR 



EUCOELOMATE PHYLA 466 



Characteristics of the Phylum, 466; The Classes of Mollusca, 468; The 

 Class Amphineura, 468 ; The Class Scaphopoda, 469 ; The Class Gastro- 

 poda, 470; The Class Pelecypoda, 471; The Anatomy of Anodonta sp., 

 472; Life History of Anodonta, 475; Economic Importance, 476; The 

 Class Cephalopoda, 477; Loligo, a Squid, 477; Other Squids, 480; Other 

 Cephalopods, 480; Some Minor Eucoelomate Phyla, 482; The Phylum 

 Bryozoa, 482 ; The Phylum Brachiopoda, 484 ; The Phylum Phoronida, 484. 



CHAPTER 26 



THE PHYLUM ARTHROPODA 486 



Characteristics of the Phylum, 487 ; Classes of the Arthropoda, 489 ; The 

 Class Onycophora, 490 ; The Class Crustacea, 492 ; The External Anatomy 

 of Cambartis, 492 ; The Internal Anatomy of Cambarns, 497 ; The Life 

 History of Cambarus, 504 ; Regeneration and Autotomy, 505 ; Biology, 

 505 ; Other Crustaceans, 505 ; Larval Stages of the Crustaceans, 508 ; The 

 Class Trilobita, 509; The Class Mcrostomata, 510; The Class Arachnida, 

 511; The Anatomy of a Spider, 511; The Biology of the Spiders, 512; 

 Other Arachnida, 513; The Class Diplopoda, 516; The Class Chilopoda, 

 516. 



CHAPTER 27 



THE CLASS INSECTA 518 



The Characteristics of the Class, 519; The Anatomy of the Grasshopper. 

 521 ; The External Anatomy of Romalea sp., 522 ; The Internal Anatomy 

 of Romalea sp., 523; Structural Variations, 527; The Mouth Parts, 527; 

 Legs, 530; Wings, 530; Sense Organs. 530; Habit Variations, 531; Para- 

 sitic Insects, 531; Social Insects, 532; Economic Relationships of In- 

 sects, 535 ; Important Orders of Insects, 536. 



