SAURUR^E. 



467 



wing of over fourteen feet, and is usually seen soaring at great 

 heights in the air, rising, it is said, to a height of over twenty 

 thousand feet. It inhabits the lofty mountain-ranges of the 

 Andes, and builds its nest at a height of from ten to fifteen 

 thousand feet. 



ORDER VIII. SAURURJE. This order includes only the 

 extinct bird, the Arch&opteryx macrura, a single specimen of 

 which and that but a fragmentary one has been discovered 

 in the Lithographic Slates of Solenhofen (Upper Oolites). 

 This extraordinary bird appears to have been about as big as a 

 Rook ; but it differs from all known birds in having two free 

 claws belonging to the wing, and in having a long lizard-like 

 tail, longer than the body, and composed of separate verte- 

 brae. The tail was destitute of any ploughshare-bone, and 

 each vertebra carried a single pair of quills. The metacarpal 

 bones, also, were not anchylosed together as they are in all 

 other known Birds, living or extinct. 



Fig. 183. ArcJuzopteryx macrura, showing tail and tail-feathers, with detached bones. 



CHAPTER LXXL 



DISTRIBUTION OF A VES IN TIME. 



As regards the geological distribution of Birds, there are 

 many reasons why we should be cautious in reasoning upon 

 merely negative evidence, and more than ordinarily careful not 



