436 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 
of which is peculiar to Australia. America possesses two genera 
and four species, each continent having a peculiar species of each 
genus. 
KEY TO THE GENERA OF RECURVIROSTRIDA. 
a. Anterior toes all extensively webbed; bill much depressed distally, nearly to 
quite as long as tarsus. 
b. Bill more or less strongly recurved; hallux present (but very small). 
Recurvirostra (p. 436). 
bb. Bill straight; halluxiabsents icc siccuncganmaces Cladorhynchus (extralimital).¢ 
aa. Anterior toes cleft nearly to base; bill terete or slightly compressed distally, much 
shorter than tarsus. (Hallux absent.).........-..----.-- Himantopus (p. 441). 
Genus RECURVIROSTRA Linneeus. 
Recurvirostra Linnaus, Syst. Nat., ed. 10, i, 1758, 151. (Type, by monotypy, 
Recurvirostra avosetta Linneeus.) ; 
Avocetta Brisson, Orn., vi, 1760,538. (Type, ‘‘ Avocetta” =Recurvirostra avosetta 
Linneus.) 
Large Recurvirostride (wing more than 200 mm.) with the long, 
slender, depressed and distinctly recurved bill nearly as long as 
tarsus, the latter covered, all round, by small, mostly longitudinal, 
hexagonal scales; anterior toes extensively webbed, and hallux present 
(though very small). 
Bill nearly to quite as long as tarsus, slender, depressed distally, 
more or less strongly recurved for terminal half, the tip of maxilla 
attenuated and decurved; nostril sub-basal, longitudinal, in lower 
part of a distinct lateral groove extending for about one-third to one- 
half the length of the maxilla. Neck rather long. Wing long and 
pointed, the longest primary (outermost, two outermost, or, rarely, 
second from outside) extending considerably beyond tips of elongated 
tertials. Tail, between one-third and one-half as long as wing, 
truncate; rectrices 12-14. Tarsus one-third as long as wing or 
longer, compressed, covered all round with small, mostly longitudinal, 
hexagonal scales, these larger and more longitudinal in front, smaller 
laterally; middle toe decidedly less than half as long as tarsus, the 
lateral toes shorter, the inner toe shorter than the outer; hallux 
minute, but with a distinct claw; anterior toes webbed, more exten- 
sively between outer and middle toes; bare portion of tibia one- 
third (R. andina) to half (R. americana) as long as tarsus, the lower 
portion scaled, like tarsus, the upper portion smooth or with scales 
indistinct. 
«Leptorhynchus (not Leptorrhynchus Guérin, 1830) DuBus, Mag. de Zool., v, 1835, 
pl. 45 (type, DL. pectoralis DuBus). Cladorhynchus Gray, List Gen. Birds, 1840, 69; 
Gen. Birds, iii, 1849, 577, pl. 155, fig. 1 (type, Leptorhynchus pectoralis DuBus). 
This genus is intermediate between Recurvirostra and Himantopus, though nearer 
to the former. The single species is peculiar to Australia. 
