FLITTERMICE. 



139 



have had their jaws ensheathed in horny beaks. The 

 skull of one species is not less than a yard in length, 

 and fragments of yet larger crania have been discovered. 



From twenty to twenty-five feet may have fallen within the 

 wing-spread of these veritable "dragons of the prime." 

 The curious point about the wing, however, and the 



