324 AMERICAN TESTUDINATA. Part H. 



surface of the intermaxillaries retreats backward from its upjDer to its lower edge; 

 their inner edges separate about half way down from the nasal opening, and slant 

 outward to the suture with the maxillaries, so that a deep, angular depression 

 is included by their lower edges; the maxillaries too have a deep depression near 

 the suture with the intermaxillaries, so that near this suture the alveolar margin 

 forms a long, sharp, tooth-lilve projection. The alveolar margin of the upper jaw 

 is sharp all round, except the lateral notches in front, which have a rounded edge. 

 The horizontal part of the alveolar surface is narrow, forming a mere ridge at the 

 front part, but it grows wider backwards. At the front end it rises steeply and 

 high up. The palatines do not project over the vomer so as to form a broad 

 roof below the palate proper, as in the Chelonioida}, and on that account the 

 passages from the nasal cavity to the mouth open directly downward. For the 

 same reason, the fleshy part of the tongue, which closes these openings when 

 the animal is breathing, is placed fui'ther forward than in the Chelonioidte. The 

 lower jaw is thin, and its margin sharp ; its front end terminates in a sharp, 

 strong, prominent point. 



The size is greater than that of any other family of the order. I have 

 seen specimens weighing over a ton. It remains to be ascertained whether this 

 family is carnivorous, as the form of the jaws seems to indicate. Though I have 

 seen several specimens upon the coasts of Florida, I could learn nothing respect- 

 ing their habits. Like the Chelonioidse, they lay a large number of eggs, as I 

 infer from the condition of the ovary; but I have never seen mature eggs. 



SECTION III. 



THE FAMILY OF CHELONIOID^. 



The family of Chelonioidse was first distinguished by J. E. Gray, and has been 

 adopted by all modern herpetologists, though not exactly with the same limits which 

 were first assigned to it, since it is now generally made to embrace also the 

 Sphargididjfi.' But, as we have already seen that the Sphargidida3 constitute a 



' With this wider extension, the Chelonioida; of first assigned to it, (Ann. of Philos., 1825.) It cor- 



modern writers answer exactly to the sub-order of responds also exactly to the sub-family Clielonina 



Chelonii, Opp., or to the family of Carettoides of Fit- of Canine, (Sagg. An. Vert. 1831,) and to the genus 



zinger, (Neue Classif., etc., 1826.) See above, p. 242. Caretta of Merrem, which is identical with the genus 



But, as characterized here, this family is strictly cir- Chelonia of Wagler, of Dumi^ril and Bibron, and of 



cumscribed within the same limits which Gray at most modem writers. 



