CONTENTS. XI 



CHAPTER XVII. 



PAGE 



Characters of the several groups of Birds ..... 295 



CHAPTER XVIII. 



The skeleton of the Wild Duck (Anas boschas) .... 302 



CHAPTER XIX. 



General account of the skeleton in Birds 328 



CHAPTER XX. 



Characters of the several groups of Mammalia .... 343 



CHAPTER XXI. 



The skeleton of the Dog (Canis familiaris) 374 



CHAPTER XXII. 



General account of the skeleton in Mammalia. The exoskeleton 



and vertebral column . .416 



CHAPTER XXIII. 



General account of the skeleton in Mammalia (continued}. The 



skull and appendicular skeleton 455 



