xlviii 



TABLE OF CONTENTS. 



and Stannius, p. 208. Classification of Lcuckart, p. 

 209. General remai-ks upon anatomical classifications, 

 p. 210. 

 Section 5. Plujsiopltihfophicdl systems. — Oken's views 

 and influence upon the progress of Zoology, p. 211. 

 His classification, p. 212. Classification of Fitzinger, 

 p. 214. Classification of McLeay, p. 216. Affinity and 

 analogy, p. 216-220. 



Section G. Emhn/ohgical systems. — InHuence of Diillin- 

 ger, p. 220. K. E. von Baer as a systematic writer, p. 

 220-226. His classification, p. 226. Classification of 

 Van Beneden, p. 227. Diagram of the development of 

 animals by Kblliker, p. 229. Classification of Vogt, p. 

 230. Further advance in perfecting the system of 

 zoology is chiefly to be expected from embrj'ological 

 investigations. 



PART II. 



NORTH AMERICAN TESTUDINATA. 



CHAPTER I. 



THE ORDER OF TESTUDINATA: ITS RANK, CLASSIFICATION, AND GENERAL CHARACTERS. 



Section 1. Bank of the TestwHnata. — The Testudinata 

 constitute an order in the class of Reptiles. The plan 

 of structure of the Vertebrata. Natural limits of the 

 class of Reptiles, p. 235-240. 



Section 2. Special classification of Testudinata. — The 

 Testudinata constitute two sub-orders, which embrace 

 several natural families, p. 241-252. 



Section 3. Essential characters of the order of Testudi- 

 nata. — Their essential character lies not so much in 

 their shield, as in the special development of the 

 different regions of the body, which assigns to them 

 the highest rank in their class, p. 252-255. 



Section 4. The Shield. — The shield consists of parts of 

 the true skeleton, and of ossifications of the skin, or 

 rather of the walls of the body, which overlie the true 

 skeleton, p. 255-257. 



Section 5. The Slcin. — The epidermis, p. 257. The 

 colors in Turtles, p. 2G1. The corium, p. 263. 



Section 6. The Skeleton. — Head, p. 265. Vertebrae, p. 

 266. Ribs, p. 267. Sternum, p. 267. Limbs, p. 267. 



Section 7. The Muscles, p. 270. 



Section 8. The Nervous System, p. 274. 



Section 9. The Organs of the Senses.- — The ear, p. 275. 

 The eye, p. 276. The nose, p. 276. The tongue and 

 mouth, p. 27 7. 



Section 10. Eating, Drinking, and Digestive Apparatus, 

 p. 278. 



Section 11. The Respiration,]). '28\. Table showing the 

 capacity of the lungs compared with the weight of the 

 body, p. 283. 



Section 12. The Vascular System, p. 2S!y. 



Section 13. The Urogenital Organs. — Urinary organs, 

 p. 287. Genital organs, p. 287. 



Section 14. The development of Turtles from a zoological 

 point of view, p. 290. Table showing the successive 

 changes in the relative dimensions of the body in Emy- 

 doid.-e, p. 292. 



Section 15. The psychological development of Turtles com- 

 pared with that of the other orders of Reptiles. Too little 

 attention is now paid to the faculties of animals, p. 296. 



Section 16. Geographical distribution of the Testudinata. 

 Great discrepancy between the range of marine Tur- 

 tles compared with that of the land and fresh water 

 types, p. 301. 



Section 17. First appearance of Testudinata upon our 

 globe, p. 303. Table showing the period of the first 

 appearance of the Testudinata compared with that of 

 the other animals, p. 306. 



Section 18. Sub-orders of Testudinata. — The sub-orders 

 of sea Turtles, Chelonii, p. 308. The sub-order of 

 fresh water and land Turtles, Amydas, p. 310. 



Section 1 9. Conclusions. — Ordinal characters are essen- 

 tially anatomical characters, and not what are com- 

 monly called zoological characters, p. 313. 



