236 DR. H. GADOW ON THE [Mar. 15, 



Cariuatse. These names are likewise open to objection, but they have 

 become household terms and they serve a practical purpose. 



Many attempts have been made to brigade together two and two 

 of my orders into combinations intermediate in value between Orders 

 and Phyla — for instance, Tubinariformes and Ardeiformes, Charadri- 

 formes and Columbiformes — but ultimately these attempts have been 

 abandoned as of little practical value. They are, however, conducive 

 to the construction of the much searched for phylogenetic tree, but 

 the very existence of such a single Avine tree is a problematic 

 idea. 



Under the heading of each group, be it subfamily, order, or sub- 

 class, is mentioned a variable number of characters. The sum total 

 of these constitutes more than a diagnosis. The single characters 

 themselves are not necessarily all those which have led to the 

 establishment of the group in question, but the sum total of the 

 characters mentioned has been thus arranged, first that it applies to 

 all the members of the group, secondly that it does not occur again 

 in those of any other group. 



Class AVES. 



Oviparous, warm-blooded, amniotic Vertebrates which have their 

 anterior extremities transformed into wings. Metacarpus and fingers 

 carrying feathers or quills. With an intertarsal joint. Not more 

 than four toes, of which the first is the hallux. 



I. Subclass ARCHORNITHES. 



First, second, and third metacarpals and fingers separate. First 

 finger with 2, second and third each with 3 phalanges. Each finger 

 with a claw. 



Upper jaw with conical teeth. 



Skeleton of posterior extremities typically avine. Feet four-toed. 

 Hallux posterior. 



YertebrEe amphicoelous. Caudal vertebrae numerous, about 21, 

 not terminating in a pygostyle. 



About 24 rectrices, attached in pairs to about 12 caudal ver- 

 tebrae. 



Ribs without uncinate processes. 



Wings with 6 or 7 well-developed primaries, attached to meta- 

 carpal III. and digits III. and II. ; 10 cubital quills. 



Extinct. Jurassic. Terrestrial — aerial. 



1. ARCHtEOPTERYGIFORMES. 



I. ArcHjEOPTeryges. 1. Archceopterygidce.. 



