1896. 



THE WING OF ARCH&OPTERYX. 



26 = 



birds; inasmuch as, according to Owen, the sacrum was "nearly 

 1 inch in breadth," while that of a common fowl measured across the 

 widest part is only three-quarters of an inch. 

 I may conclude by offering a 



Summary of the Characters of Avdueoptcvyx. 



Reptilian. — Skull : Upper jaw and mandible armed with teeth, 

 apparently set in sockets (Thecodont dentition). 



Vertebral column : Centra of vertebrae with fiat articular 

 surfaces (Dames apud Hurst). Caudal vertebras numerous, forming 



Fig. 2. 



-Arch.eopteryx lithographica, restored after the fossil in the 

 Berlin Museum. 



a long lizard-like tail, and each vertebra furnished with a pair of 

 rectrices. 



Ribs : The dorsal ribs have been described as wanting uncinate 

 processes ; an unsafe conclusion, since these are often absent in the 

 skeletons of existing birds, having been lost in maceration. The 

 cervical ribs appear to have been much more slender than in modern 

 birds, and to have remained moveably articulated throughout life. 

 " Abdominal ribs," resembling rather those of the Crocodilia than of 

 the Chameleonida, appear to have been present. 



Manus : Digit III had four phalanges, the last of which was 

 armed with a claw. 



The characters just enumerated have passed more or less entirely 



u 



