GEOGRAPHICAL ZOOLOGY. 
[part IV. 
intermediate between the Anserine birds on the one side and 
the Storks and Herons on the other.” The pterolysis according 
to Nitzsch is “ completely stork-like.” 
General Remarks on the Distribution of the Grallce, or Wading 
and Running Birds. 
The Waders, as a rule, are birds of very wide distribution, 
the four largest families Pallidas, Scolopacidee, Charadriidse and 
Ardeidoe, being quite cosmopolitan, as are many of the genera. 
But there are also a number of small families of very 
restricted distribution, and these all occur in the two most 
isolated regions, the Neotropical and the Australian. The 
Neotropical region is by far the richest in varied forms of 
Waders, having representatives of no less than 15 out of the 19 
families, while 7 are altogether peculiar to it. The Australian 
region has 11 families, with 1 peculiar. The other tw T o tropical 
regions each possess 11 families, but none are peculiar. The 
Palaearctic region has 10, and the Nearctic 7 families. No less 
than three families — Chionididae, Thinocorkke, and Cariamidm — 
are confined to the Temperate regions and highlands of South 
America ; while four others, — Aramidae, Psophiidm, Eurypygidse 
and Palamedeidm, — are found in Tropical America only ; and 
these present such an array of peculiar and interesting forms as 
no other part of the globe can furnish. The Phcenicopteridse or 
Elamingoes, common to the Tropical regions of Asia, Africa and 
America, but absent from Australia, is the only other feature 
of general interest presented by the distribution of the Waders. 
The Order contains about 610 species, which gives about 32 
species to each family, a smaller average than in the Gallium 
or Accipitres, and only about one-fourth of the average number 
in the Passeres. This is partly due to the unusual number 
of very small families, and partly to the wide average range of 
the species, which prevents that specialization of forms that 
occurs in the more sedentary groups of birds. 
