X CONTENTS. 



CHAPTER XXI. 



General characters of the Cephalopoda — Reproductive process in 

 the Cuttle-fishes — Shell of the Cephalopoda— Dibranchiata 

 — Tetrabranehiata — Orthocerata — Ammonites, . . 208-217 



CHAPTER XXII. 



General characters of the Vertebrata — Skeleton of Vertebrates — 

 Structure of a vertebra — Vertebral column — Limbs of Ver- 

 tebrates — Digestive system — Circulatory system — Respira- 

 tory system — Nervous system — Reproduction — Primary 

 divisions — Ichthyopsida — Sauropsida — Mammalia, . 218-227 



CHAPTER XXIII. 



General characters of the Fishes — Scales — Endoskeleton — Limbs 

 — Tail — Digestive system — Circulation — Respiration — Ner- 

 vous system — Organs of hearing and smell — Reproduction, . 228-236 



CHAPTER XXIV. 



Orders of Fishes — Pharyngobranchii — Marsipobranchii — Teleostei 

 • — Sub-orders of the Teleostei — Ganoidei — Elasmobranchii — 

 Sub-orders of the Elasmobranchii — Dipnoi, . . . 237-248 



CHAPTER XXV. 



General characters of the Amphibia — Orders of the Amphibia — 



Ophiomorpha — Urodela — Anoura — Labyrinthodontia, . 249-2.56 



CHAPTER XXVI. 



General characters of the Reptilia — Circulatory and Respiratory 



systems — Divisions, . ... 257-260 



CHAPTER XXVII. 



Orders of Reptilia — Chelonia — Ophidia — Lacertilia — Crocodilia — 

 Ichthyopterygia — Sauropterygia — Pterosauria — Anomodon- 

 tia — Deinosauria — Theriodontia, . . 261-277 



CHAPTER XXVIIL 



General characters of the class Aves — Feathers — Vertebral column 

 — Anterior extremity and pectoral arch — Posterior extremity 

 and pelvic arch — Digestive system — Respiration — Circula- 

 tory system — Nervous system — Organs of the senses — Migra- 

 tions of Birds, ....... 278-289 



