MACKIE — THE AERONAUTS OF THE SOLENHOFEN AGE. 



5 



ostrich are thus reduced to nine in the adult. In the retention of 

 the separate vertebrae of the tail, the Archseopteryx presents an ex- 

 ample of the persistence of embryonic or more generalized characters, 

 and affords a demonstration of the great truth, often obscured of late 

 years, that there exists a certain representation of the career of any 

 single animal in the various stages through which the life system of 

 the world has passed. 



If there be any who yet eutertain a doubt of the ornithic character 

 of the specimen, and are misled by the occurrence of Archseopteryx 

 in the Solenhofen slate, the very metropolis of Pterodactyles, to 

 suspect any reptilian affinities for it, we hope that they will compare 

 the hind foot of the Archseopteryx with that of any bird, and with 

 that of the longtailed Pterodactyle (E-amphorhynchus) from the 

 same Solenhofen beds, in the British Museum. In the birds we see 

 the foot compact, stout, with an opposable hinder unguiculate digit, 

 capable of prehension or of active support. In the reptile the hoino- 



DlSTRIBUTION OF BlEDS. 



^atatores. 



Gralla^ 



Easores. 



Insessores Scansores. Volitores. Eaptores. ^eiices*" 



— mr\ i 



Strata. 



Eecent. 



Pliocene. 



Miocene. 



Eocene. 



Cretaceous 



Greens and 



Wealden. 



Oolite. 



Lias? 



Trias ? 



Permian. 



Carboni- 

 ferous. 



