1873.] 5d [Ridgway. 



The following table will show more exactly the relationship between 

 these two remarkable genera : — 



Common Characters. Form very slender and elongated, fitted 

 for a terrestrial life. Head small, bill weak, tarsi long and slender, 

 and remiges and rectrices much developed, the secondaries very 

 broad and elongated, but shorter than the longest primaries. Outer 

 toe much shorter and weaker than the inner; tibio-tarsal joint flex- 

 ible in both directions. Tarsus more than twice as long as the mid- 

 dle toe. Tail nearly as long as the wing, rounded. Coloration: — 

 Ashy or blackish, the lower parts usually with white bars; tail black 

 with white bands. 



Geranospiza. Whole head normally feathered. Tarsi with a 

 frontal and posterior series, or single row, of broad, regular, trans- 

 verse scutellse. Hab. Tropical America. 



Polyboroides. Whole side of the head naked, including lore, 

 lower jaw, superciliary region and temporal region. Tarsi reticulated, 

 or covered uniformly with small longitudinally hexagonal scales. 

 Hal. Southern Africa. 



SYNOPSIS OF THE SPECIES OF GERANOSPIZA. 



1. G. gracilis. Crissum whitish, plain, or sparsely barred. 

 Wing, 11.00-15.25; tail, 9.75-12.50; culmen, .75-.80; tarsus, 2.95- 

 4.30; middle toe, 1.15-1.60. Deep plumbeous above, uniform, except 

 on the wings ; lower parts, and sometimes the wing-coverts, barred 

 transversely with white; primaries, plumbeous-black, with an obscure 

 plumbeous spot about the middle portion. Tail, deep ochraceous, 

 narrowly tipped with white, the terminal half crossed by two distinct 

 bands of black — the last subterminal ; the intermedia? crossed by 

 about three bands each of black and whitish, of about equal width, 

 the posterior light band having an ashy cast. 



Hab. Paraguay and Brazil. 



2. G. c.erulescens. Crissum plumbeous or black, with or 

 without bars. Wing, 10.00-13.80; tail 8.00-11.00; culmen, .G8-.85; 

 tarsus, 2.90-3.60; middle toe, 1.12-1.50. Uniform plumbeous or 

 plumbeous-black, usually without white bars, but occasionally with 

 faint ones on the lining of the wing, tibia?, or other portions of the 

 lower parts. Primaries and t ail black, the latter tipped with white, 

 and crossed by about three distinct bands of white, much narrower 



