1222 



CLASS AVES. 



differs from that of all other known Birds in that it consists of a 

 series of long vertebrae, gradually tapering to the extremity, and 

 each of which carries a pair of feathers. From the absence of 

 impressions of feathers in the region of the body, it has been 

 thought that only the wings and tail had these appendages ; but 

 it is far more probable that the feathers had fallen from the body 

 as it lay on the old sea-shore, while those of the wings and tail still 



Fig. i no. — Part of the skeleton, wiih impressions of the feathers of the wings and tail, of 

 ArchcBOpteryx macrura ; from the lithographic limestone of Bavaria. Reduced. 



adhered to their attachments. In the figure of the British Museum 

 specimen of A. macrura (fig. mo) the head is not shown; but it 

 exists in an imperfect state of preservation in the slab. Till we 

 know more of the other Birds of the Jurassic, the true relationship 

 of Archceopteryx to existing forms cannot be determined. 



Order II. Ratit^:. — The Ratitse, or Struthious Birds, differ 

 from the preceding order by the anchylosis of the metacarpals 

 (when present) and the short tail, which may terminate in a 

 pygostyle. They are further characterised by the sternum (figs. 

 1 105, mi) being devoid of a keel; by the long axes of the 

 adjacent portions of the scapula and coracoid being approximately 

 in the same line (fig. 11 n), or at least forming an exceedingly 

 obtuse angle at their junction ; by the wings being useless for 

 flight; and by the peculiar characters of the pelvis (figs. 1107, 

 1 1 12), which have been already mentioned. There are, moreover. 



