114 POPULAR SCIENCE MONTHLY. 



WINGED EEPTILES. 



By Professor S. W. WILLISTON, 

 university of kansas. 



OF the cold-blooded, air-breathing animals known as true reptiles 

 there are now in existence upon the globe more than four thou- 

 sand species, classified by naturalists in four very distinct groups or 

 orders — the Ehynchocephalia, Crocodilia, Chelonia and Squamata. Of 

 the Ehynchocephalia, there is but a single species now living, the Tuatera 

 or Sphenodon, confined to the islands off the northeast of ISTew Zealand, 

 and very rare. It is a small animal, seldom attaining a length of twenty 

 inches, lizard-like in habits and appearance. Though now so near ex- 

 tinction, the order during Paleozoic times was an important one, both 

 in size and variety. No older reptiles are known. 



The Crocodilia, inclusive of the alligators and gavials (better 

 garials) number at the present time scarcely twenty-five species, confined 

 to tropical and subtropical shores of both the old and the new worlds. 

 Of great size, cruel and sluggish in disposition, they seem to be a re- 

 minder of those times when size, rapacity and cruelty characterized 

 their class on land, in the air and in the water. Though approaching 

 extinction, these modern representatives of what was at one time a far 

 more numerous and widely distributed order are the specialized de- 

 scendants of an ancestral line scarcely less ancient than the rhyncho- 

 cephalian. In form and size, and probably also in habits, the croco- 

 dilia have varied comparatively little throughout the greater part of 

 their long period of existence upon the earth. 



Were none of the Chelonians — the tortoises and turtles — now living, 

 the extinct forms would appear to us among the most remarkable of 

 vertebrate animals, so little interest do familiar things incite. Like 

 the crocodilia and rhynchocephalia, they are among the oldest of rep- 

 tiles; 3'et in number and variety at the present time they are inferior 

 only to the lizards and snakes, and may truly be said, after the lapse of 

 many millions of years, to be only now at or but recently past the zenith 

 of their development. In the past there have been species perhaps twice 

 or thrice as large as any now in existence — from the Bad Lands of 

 Dakota there is known one sea-turtle twelve or more feet in expanse 

 of shell, with a skull nearly as large as that of a horse — but in type of 

 structure the very oldest that we know differed but slightly from some 

 that are now living. 



