SUB-ORDER 
CLAM ATORES. 
In the present state of our knowledge of the subject, it is a matter of some uncertainty 
whether the North American Anisoclactyle birds, viz : the Alcedinidae and Prionitidae, belong 
more naturally to the Strisores or to the Clomatores of Cabanis' arrangement, [Strisores and 
Traclieoplwnes of Burmeister.) However, although in some respects of closer affinities to the 
former, I propose to keep them with the Clamatores, in accordance with the views of Cabanis. 
They may he grouped as Ayiisodactyli, in distinction from the remaining families of the 
sub-order, or Tracheophones, although neither of these names is to be taken in the extended 
signification given it by Muller and others, hut merely as having provisional reference to the 
North American species alone. 
The muscles of the lower larynx, in some families, are weak and simple as in the Strisores ; 
in others again they form a powerful fleshy "body, which covers the first bronchial ring. These 
birds have a harsh voice, capable of but little modulation. 
The following schedule will he sufficient to indicate the general characters of the different 
families of this sub-order found in North America, although there are many others from other 
parts of the world not taken into account : 
ANISODACTYLI. 
Outer toe much longer than the inner ; united for half its length to the middle so as to 
have a common sole to this extent. Sole of the hind toe widened and continuous 
internally with that of the inner toe. Tail usually with twelve feathers, sometimes 
with ten. 
Alcedinidae. — Tongue small, rudimentary. Tarsi very short. Edge of bill plain. 
Prionitidae. — Tongue of normal size. Tarsi rather long. Cutting edge of bill 
dentated. 
TRACHEOPHONES. 
Eeet and wings much as in the lowest Oscines. Lateral toes usually nearly equal. Tail 
generally of twelve feathers. 
Colopteridae. — Tarsus more or less enveloped by scutellae. Posterior portion of 
the tarsus with small plates, sometimes partly naked. Wings sometimes with 
peculiarly abbreviated primaries. Bill short, conical, and usually depressed, 
the tip sometimes abruptly hooked. 
