322 CHARADRIIFORMES CHAP. 
akin to Grouse, they have since given rise to much discussion ; 
Dr. Gadow’s view—here adopted—being that they are highly 
specialized forms, analogous to the Galli in their digestive 
organs, but homologically constituting a link between the 
Limicolae and the Columbae.". From the Pigeons they certainly 
differ remarkably in the condition of the chicks, which are 
covered with brown, creamy, and black down, and run almost 
immediately from the shell; yet they agree with them in most 
points of osteology, myology, and pterylosis, while the eggs recall 
those of Rails, and the flight resembles that of a Plover. 
The body is compact; the bill short, arched, and fairly stout ; 
the metatarsus abbreviated and feathered anteriorly, or entirely 
in Syrrhaptes. In this genus, moreover, the hallux, much re- 
duced elsewhere, is totally absent; and the short front toes are 
enclosed in a sort of casing, which is covered as far as the thick 
claws with hairy plumage, the whole forming a padded foot unique 
among Birds. The long pointed wings have sixteen or seventeen 
secondaries, and eleven primaries, of which the outer has its 
shaft produced into a thin filament in Syrrhaptes paradoxus ; 
the wedge-shaped tail has sixteen rectrices, the median pair 
being elongated and pointed in that genus and Pteroclurus (Pin- 
tailed Sand-Grouse), if the latter be allowed to stand. The 
furcula is U-shaped, the syrinx tracheo-bronchial, the tongue 
lanceolate; there is a small aftershaft, and a large crop; while 
the down of the adults is sparingly distributed. 
Sand-Grouse are true desert-birds, affording excellent in- 
stances of protective coloration in their buff or brownish tints, 
sheghtly varied with grey, black, orange, and white; Pterocles 
fasciatus and P. lichtensteini, however, prefer bushy and rocky 
ground to bare, sandy, or stony plains. Gregarious yet mono- 
gamous, they are shy and wary, but very pugnacious among 
themselves; their flight is swift, strong, and noisy ; their powers 
of walking and running good, though rather clumsy, owing to the 
extremely short legs. All the species le closely until Hushed, and 
are fond of basking in the sun on their sides, in holes scraped out 
for the purpose. Migration probably prevails to some extent 
throughout the Family, while the irruptions of Syrrhaptes para- 
doxus into Europe (p. 324) are quite unparalleled. The cry, 
often uttered upon the wing, is a piercing whistle, or a twittering 
1 P.Z.S. 1882, pp. 312-332 ; Bronn’s Thier-Reich, Aves, Syst. Theil, pp. 207-209. 
