458 BIRDS OF BRITISH GUIANA. 



Genus SPIZA Bonap. 



Spiza Bonaparte, Journ. Philad. Acad. iv. p. 45, 1824. Type S. ameri- 

 cana (Gmel.). 



Fig. 172. — Spiza americana. 



This monoiypic genus is easily distinguished by its square tail 

 with its obliquel3'--cut and pointed feathers. The bill is somewhat 

 stout and pointed, the depth and width at the base are about equal, 

 and is about three-fourths the length of the exposed culmen. 

 The wing is rounded, the first, second, and third primaries are 

 longest and equal. The tail is square at the tip and about five- 

 eighths the length o£ the wing. The tarsus is about twice the 

 length o£ the exposed culmen. Coloration : male and female 

 similar, 



639, Spiza americana. 



Black-throated Bunting. 



Umberiza americana Gmel. Syst. Nat. i. p. 872, 1789 (New York). 

 Spiza americana Sharpe, Cat. B. Brit. Mus. xii. p. 770, 1888 ; Bi-abourne 

 &.Chubb, B. S. Amer. i. p. 375, no. 3853, 1912. 



Adult male. Grown of head dark yellowish green, with minute 

 dark shaft-lines to the feathers ; hind-neck, sides of face, and 

 ' sides of neck slate-grey ; upper back black with broad ash-brown 

 margins to the feathers becoming rufous-brown on the scapulars 

 where the shaft lines are narrower; lower back, rump, and upper 

 tail-coverts dark earth-brown; lesser and median upper wing- 

 coverts chestnut; greater upper wing-coverts and inner secon- 

 daries blackish broadly margined with rufous-brown ; bastard- 

 wing, primary-coverts, and flight-quills dark hair-brown, with 

 pale inner edgings to the last ; tail hair-brown ; lores, a line over 

 the eye, and cheeks yellow like the fore-neck and middle of the 

 breast ; short feathers under the eye, a line along the sides of the 



