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Show 236 DR. H. G A D O W ON T H E [Mar. 15, Carinatae. 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 m y 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 subclass, 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 A R C H O R N I T H E S . 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. Vertebrae amphiccelous. Caudal vertebrae numerous, about 21, not terminating in a pygostyle. About 24 rectrices, attached in pairs to about 12 caudal vertebrae. Ribs without uncinate processes. Wings with 6 or 7 well-developed primaries, attached to metacarpal III. and digits III. and II.; 10 cubital quills. Extinct. Jurassic. Terrestrial-aerial. 1. ARCILEOPTERYGIFORMES. I. ARCH^OPTERYGES. 1. Archceopteryyidce. |