2370 CROCODILES, DINOSAURS, AND FLYING DRAGONS 



latter being the median bar seen in the lower figure of the illustration on p. 2367, 

 A further peculiarity is the presence of seven or eight pairs of abdominal ribs in the 

 wall of the abdomen, which have no connection with the proper ribs, and have 

 their angle of union directed forward.* As regards the soft parts, the heart differs 

 from that of all other living Reptiles in having four complete chambers, so that 

 the fresh and impure blood can only mingle by means of a communication between 

 the great vessels externally to the heart, while there is also an incomplete midriff 

 dividing the chest from the abdomen. 



In addition to the preceding characteristics, which are common to all members 

 of the order, there are certain others found only in the existing forms and some of 

 their nearest extinct allies. One of the most remarkable of these peculiarities is 

 the extremely backward position of the aperture of the internal nostrils, which in 

 the dried skull, as shown on p. 2358, is situated close up to the occiput, this being 

 due to the development of special plates by the bones of the palate, which grow 

 beneath the nasal passage, so as to form a floor to it, and thus completely cut it off 

 from the cavity of the mouth. As the summit of the windpipe is continued upward 

 into this posterior aperture of the nostrils, crocodiles are enabled to breathe while 

 their mouths are wide open and filled with water. . Another distinctive feature of 

 the group, also shown in the figure just referred to, is that the socket for the eye 

 communicates freely behind with the lower temporal fossa. Then, again, all exist- 

 ing members of the order are characterized by the bodies of the vertabrse having 

 the ball behind and the cup in front; while the ribs of the chest are provided with 

 hook-like or uncinate processes resembling those of birds. In the region of the 

 neck the ribs present the peculiarity of having backwardly projecting and overlap- 

 ping processes, which effectually prevent these animals from turning their heads to 

 one side. 



Crocodiles are denizens of the tropical and subtropical regions of 

 the globe, and are found in such latitudes wherever there are rivers 

 or fresh- water lakes of sufficient size for their mode of life; while one of the Indian 

 species habitually resorts to the seacoast, where it has been seen floating at a con- 

 siderable distance from the land. All of them are excellent swimmers, and are 

 mainly propelled when in the water by the aid of their powerful tails; the limbs 

 being chiefly used when walking at the bottom of the water, or on the shore. 

 When in repose, crocodiles lie like logs either in the water or on the banks of the 

 lakes or rivers they inhabit, but when in pursuit of their prey in the water they 

 move with great speed, while they are also active on land. The young are, how- 

 ever, decidedly nimbler in their movements than are the adults. Exclusively car- 

 nivorous in the diet, some members of the order feed solely upon fish; while others, 

 in addition to fish, prey upon the flesh of all animals that come in their way. Adult 

 crocodiles, writes Dr. Giinther, "attack every large animal which accidentally 

 approaches them, and in overpowering it the whole of their powerful organization 

 is called into requisition. Seizing the victim between their capacious jaws, and 

 fastening their long pointed, conical teeth into its flesh, they draw it, in one mo- 



* These abdominal ribs, connected together by the ligament, are shown in the figure before referred to. 



