TABLE OF CONTENTS. 



xlix 



CHAPTER II. 



THE FAMILIES OF TESTXJDINATA. 



Sf.CTIOn 1. General remarks tipnn families. — The method 

 <'encraUy adopted in limiting families is defective. To 

 arrive at satisfactory results, it is necessary to ascertain 

 by careful comparisons what are the structural elements 

 which constitute the diflcrcnt patterns of the families, 

 p. 317-320. 



•Section 2. Thefainiltj of Sphargididn-, p. 320. 



Section' 3. Thefamil// of Clielonioiikc, j>. 324. 



.Section 4. The family of Trionyclddm, p. 329. 



Section 5. The family of Chelyoiihc, p. 335. The Ster- 

 notheroidie, PelomedusiE, Ilydraspidcs, Chelodinoida", 

 and Podocnemides, note, p. 339. 



Section' C. The family of f'hely'!ri>ii//r, p. 341. 

 Section 7. The family of CinoslernoiihB,\i. SAG. 

 Section 8. The family of Kiiiy(liiiila'.\).'S:>\. Sub-families: 



NectcmydoidiC, Deirochelyoidic, Evemydoidie, C'lemmy- 



doidie, Cistudinina, p. 355-356. 

 Section 9. The family of Testuilinina, p. 35G. 

 Section 10. On the brain of the different families of North 



American Turtles. The brain is typical for different 



families among Vertobrata. p. 362. 

 Section 11. Differences in the mode of life of Tesluilinala. 



The natural limits of families do not always coincide 



with the mode of life of their representatives, p. 3G5. 



CHAPTER III. 



NORTH AMERICAN GENERA AND SPECIES OF TESTUDINATA. 



Section 1. General remarks upon the North American 

 genera and species of Testudinata. — How the genera 

 of Testudinata ought to bo characterized, and how they 

 compare with genera in other classes, p. 367. 



Section 2. J'Ae genus Spharyis, p. 371. Sphargis coria- 

 cea, p. 373. Identification and range of distribution of 

 the species, p. 373. 



Section 3. The genera and species of Chetunioida', p. 375. 

 Chelonia, p. 377. Chclonia Mydas, p. 378. Chelonia 

 virgata, p. 379. Eretmochelys, p. 380. Eretmochelys 

 imbricata, p. 381. Eretmochelys squamata, p. 382. 

 Thalassochelys, p. 383. Thalassoehclys Caouana, p. 

 384. 



Section 4. Comparison of the growth of the Chelonii teith 

 that of the Amydce, p. 38fi. 



Section 5. The genera of Trionychidtp, p. 394. Amyda, 

 ]). 398. Amyda mutica, p. 399. Platypeltis, p. 400. 

 Platypcltis forox, p. 401. Aspidoncctos, p. 403. Aspi- 

 donectcs spinifcr, p. 403. Aspidonectcs a.-sper, p. 405. 

 Aspidonecfes nuchalls, p. 4ih;. Aspidoncctes Emoryi, 

 p. 407. 



Section 6. The genera of Chetyilroidir, p. 409. Gypo- 



G 



chelys, p. 413. Gypochelys lacertina, p. 414. Chely- 

 dra, p. 416. Chelydra serpentina, p. 417. 



Section 7. The genera of Cinosternoida, p. 418. Sub- 

 family of Ozothccoidic, p. 423. Goniochelys, p. 423. 

 Goniochelys triquetra, p. 423. Goniochelys minor, p. 

 424. Ozothcca, p. 424. Ozntheca odorata, p. 425. 

 Ozotheca tristycha, p. 425. Sub-family of Cinoster- 

 noidse, p. 426. Ciuosternum, p. 426. Thyrosternum, 

 p. 427. Tliyrostcrnuni pcnnsylvanicum, p. 428. Thy- 

 rosternum sonoricnse, p. 428. Thyrosternuin integrum, 

 p. 429. Platythyra, p. 429. Platythyra llavescens, 

 p. 430. 



Section 8. The genera of Emydoidre, p. -iSO. Sub-family 

 of NectcmydoidiB, p. 431. Ptychemys. p. 431. Pty- 

 chomys rugosa, p. 431. Ptychemys concinna. p. 432. 

 Ptychemys mobiliensis, p. 433. Ptychemys liieroglyph- 

 ica, p. 434. Ptychemys dccussata, p. 434. Trachemys, 

 p. 434. Trachemys scabra, p. 434. Trai-liemys Troos- 

 tii, p. 435. Trachemys elegans, p. 435. Trachemys 

 rugosa. [i. 436. Ciraptemys, p. 436. Graptcmys geo- 

 graphica.p. 436. Graptcmys LeSueurii. p. 436. Mala- 

 coclcuunys, p. 437. Malacoclemmys palustri.s, p. 437. 



