Contents 15 



CHAPTER 28 Page 



THE PHYLUM ECHINODERMATA AND RELATED GROUPS 541 



Characteristics of the Pliyhim, 542 ; The Classes of the Echinodermata, 

 544 ; The Class Asteroidea, 544 ; The Anatomy of Astcrias forbesi, 544 ; 

 The Life History of A. forbesi. 547; The Biology of A. forbesi, 548; The 

 Class Ophiuroidea, 549 ; The Class Echinoidea, 550 ; The Class Holothu- 

 rioidea, 551; The Class Crinoidea, 553; The Phylum Chaetognatha, 554; 

 The Phylum Enteropneusta, 556. 



CHAPTER 29 



THE PHYLUM CHORDATA 559 



The Protochordates and Fishes, 559; Characteristics of the Phylum, 560; 

 Subphyla of the Chordata, 561 ; The Subphylum Urochordata, 561 ; The 

 Classes of the Subphylum, 561 ; The Anatomy of Molgula, 562 ; The Sub- 

 phylum Cephalochordata, 564 ; The Anatomy of Branchiostoma, 564 ; The 

 Subphylum Vertebrata, 566 ; The Classification of the Subphylum Verte- 

 brata, 567 ; The Origin and Development of the Pisces, 567 ; The Class 

 Agnatha, 570 ; Characteristics of the Class, 570 ; Divisions of the Class 

 Agnatha, 570 ; Anatomy of Pctroinyzon viarinus, the Sea Lamprey, 571 ; 

 The Life History of Petroinyzon viarinus, 573 ; Economic Importance of 

 Petromyzon, 573; Other Cyclostomes, 575; The Class Chondrichthyes, 

 575 ; The Characteristics of the Class, 575 ; The Classification of the Class 

 Chondrichthyes, 576; The Anatomy of Squahis acanthias. the Dogfish 

 Shark, 576 ; Other Elasmobranchs, 579 ; The Chimaeras, 581 ; Economic 

 Importance, 581 ; The Class Osteichthyes, 581 ; Characteristics of the Class 

 Osteichthyes, 582; The Subclasses of the Class Osteichthyes, 582; The An- 

 atomy of the Perch, Perca flavescens, 583 ; Tail and Scale Variations, 587 ; 

 Migration of Fish, 587 ; Economic Importance of Fish, 588 ; Orders of the 

 Class Osteichthyes, 588. 



CHAPTER 30 



THE TETRAPODA : AMPHIBIA, REPTILES, AND BIRDS 592 



The Class Amphibia, 595; Characteristics of the Class Amphibia, 595; 

 The Classification of the Modern Amphibia, 596; Biology of the Am- 

 phibians, 597; Urodela, 597; Anura, 598; Apoda, 601; Economic Ini- 

 portance of the Amphibians, 601 ; The Class Reptilia, 601 ; Characteristics 

 of the Class Reptilia, 602 ; Classification of the Class Reptilia, 603 ; The 

 Order Chelonia (the Turtles), 604; The Order Squamata (the Lizards 

 and Snakes), 606; Snake Legends, 610; The Order Crocodiha. 610; 1 he 

 Order Rhynchocephalia, 611; The Fossil Reptiles, 612; The Class Aves, 

 614; Characteristics of the Class Aves, 615; The Classification of the 

 Class Aves, 617; The Biology of Birds, 617; Structural Variations 617; 

 Habit Variations, 620; Migration, 621; Economic Importance of Birds, 

 623 ; The Orders of Birds, 623. 



CHAPTER 31 



THE TETRAPODA : MAMMALS 626 



Characteristics of the Class, 628: The Classification of the Mammals 629; 

 The Orders of Mammals, 630; Order Monotremata, 630; Order Marsu- 

 pialia, 631 ; Order Insectivora, 633 ; Order Dermoptera 634; Order Chirop- 

 tera, 634; Order Primates, 634; Order Pholidota 635 ; Order Edentata 

 635; Order Lagomorpha, 635; Order Rodentia 636; Order Cetacea, 637 

 Order Carnivora. 638; Order Tubulidentata, 638; Order Proboscidea, 639 

 Order Hvracoidea, 639; Order Sirenia, 639 ; Order Perissodactyla, 639 

 Order Artiodactyla, 640 ; Man and His Development 640 ; South Africa 

 Discoveries, 641 ; Fossil Men From the Orient, 642 ; Fossil Men From 

 Europe, 642. 



