TABLE OF CONTENTS. vii 



CHAPTER XIX. 



General characters of the Mollusca Primary divisions of the Mollusca, . Pages 164-1 6T 



CHAPTER XX. 



Molluscoida General characters of the Polyzoa General characters of the Tunicata Gen- 

 eral characters of the Brachiopoda, p. 168-175 



CHAPTER XXI. 



Classes of the Mollusca Proper General characters of the Lamellibranchiata General char- 

 acters of the Gasteropoda Nudibranchiata Heteropoda Air-breathing Gasteropods 

 Pteropoda, p. 176-186 



CHAPTER XXII. 



General characters of the Cephalopoda Reproductive process hi the Cuttle-fishes Shell of 

 the Cephalopoda Dibranchiata Tetrabranchiata Orthocerata Ammonites Tabular 

 view of the main divisions of the Mollusca, p. 187-194 



CHAPTER XXIII. 



General characters of the Vertebrata Skeleton of Vertebrates Structure of a Vertebra 

 Vertebral column Limbs of Vertebrates Digestive system Circulatory system Re- 

 spiratory system Nervous system Reproduction Primary divisions Ichthyopsida 

 Sauropsida Mammalia, p. 195-205 



CHAPTER XXIV. 



General characters of the Fishes Scales Endoskeleton Limbs Tail Digestive system 

 Circulation Respiration Nervous system Organs of hearing and smell Reproduc- 

 tion, ....... .p. 206-213 



CHAPTER XXV. 



Orders of Fishes Pharyngobranchii Marsipobranchii Teleostei Sub-orders of the Tele- 

 ostei Ganoidei Elasmobranchii Sub-orders of the Elasmobranchii Dipnoi, 



p. 214-224 



CHAPTER XXVI. 



General characters of the Amphibia Orders of the Amphibia Ophiomorpha Urodela 

 Anoura Labyrinthodoutia, p. 225-233 



CHAPTER XXVII. 



General characters of the Reptilia Circulatory and Respiratory systems Divisions, 



p. 234-237 



CHAPTER XXVIII. 



Orders of Reptilia Chelonia Ophidia Lacertilia Crocodffia Ichthyopterygia Saurop- 

 terygia Pterosauria, p. 238-252 



CHAPTER XXIX. 



General characters of the Class Aves Feathers Vertebral column Anterior extremity 

 and pectoral arch posterior extremity and pelvic arch Digestive system Respira- 



