SAURIA. 293 



long and thirty-four wide, and sternum twenty-eight inches 

 long. It is frequently seen in mid-ocean floating upon 

 the waves, apparently asleep. 



SPHARGIDIDJE, OR SpHARGis FAMILY. This Family 

 comprises turtles whose general form is something like 

 that of a flattened pyramid, and the body is covered with 

 a thick coriaceous skin, instead of a hard shell. Sphargis 

 is the only genus, and is represented by 5. coriacea, Gray, 

 of the Atlantic and Mediterranean, which is the largest 

 of all turtles, attaining the weight of twelve hundred to 

 two thousand pounds, in some cases. One caught in 

 Chesapeake Bay had a total length of almost eight feet. 



Fossil turtles are found in both continents. 



SUB-SECTION II. 



THE ORDER OF SAURIA, SAURIANS, OR LIZARDS. 



THE Order of Sauria comprises scaly reptiles whose 

 body is destitute of a shell, much elongated, and the tail 

 generally long, and whose mouth is large, and armed with 

 teeth. With few exceptions, they have four feet, which 

 are generally furnished with nails. The ribs are mov- 

 able, partially connected to the sternum, and are raised 

 and depressed in respiration. The lungs generally ex- 

 tend far into the abdominal cavity. It comprises the 

 Crocodilidae or Crocodile Family,* Lacertinidae or true 

 Lizard Family, Iguanidae or Iguana Family, Geckotidae 

 or Gecko Family, Chameleonidae or Chameleon Family, 

 Scincoidae or Skink Family, Chalcidae or Glass-snake 

 Family, and many fossil reptiles, f 



* Regarded as an Order by many authors. 



f The Triassic, Jurassic, and Cretaceous rocks, in some localities, abound 

 with the remains of extinct reptiles, and many of them, in the two latter 

 groups especially, are those of Saurians of the most wonderful, and, in 

 many cases, gigantic forms. The Megalosaurus was a terrestrial Saurian, 

 thirty feet long. The Iguanodon, herbivorous in its habits, was thirty feet 



