HIRUNDO. 



295 



than that of under parts, and more continuous, though sometimes 

 there is but little difierence in the shade. The space just posterior 

 to the collar generally appears lighter than on the belly. Usually, 

 however, the rufous wash of under parts is decidedly paler than that 

 of throat and forehead ; sometimes quite pale ; in only one or two 

 instances as light as European specimens (as 6,020 and 29,294). In 

 such cases, however, the absence of broad jugular band of continuous 

 black, and the shorter tail, will distinguish from the European bird. 



There is an occasional tendency to a widening of the jugular 

 collar, especially in young birds, but this is so much mixed with 

 rufous feathers as to be easily understood. 



In young birds the frontal chestnut band is considerably reduced 

 in size, and generally paler and duller in color. 



The largest specimen of H. ho7-reorum I have seen is No. 19,542, 

 from Fort Rae. Here the wing measures 4.90, and the tail 4.50 

 (the usual length of tail is under 4.00) ; the next largest specimen 

 being No. 34,349, from the Rocky Mountains. The maximum length 

 of tail in specimens of H. rustica, of Europe, before me, is 5.00 — 

 the average being perhaps 4.50. 



The series of specimens from western America is not sufficient to 

 determine whether there is any essential difference ; the bill, however, 

 appears decidedly smaller. 



I regret very much that the specimens from South America* at my 

 command are too few to make a satisfactory comparison with the 

 North American bird. There appears, however, to be a difference 

 in a rather smaller bill, and in having the gloss of the upper parts 

 steel green, rather than purple or violet. I am, however, much 

 inclined to doubt whether there is any specific difference. The 

 chestnut brown of the forehead is quite as deep and extensive as in 

 the northern bird, although Burmeister describes it as whitish, pass- 

 ing behind into rust-yellow, and speaks of the whole under parts 



' Hirundo erythrogaster. 



Hirundo erythroyaster, BoDD. Tabl. PI. enl. (724, fig. 1), 1783, 45 (Cay- 

 enne). — ScLATEE, Catal. 1861, 39 (Brazil). 



Hirundo Tufa, Gm. S. Nat. I, 1788, 1018 (PI. enl. 724, fig. ]).— Bdrm. 

 Ueb. Ill, 148 (Brazil). 



Hirundo cyanopyrrha, Vieill. Nouv. Diet. XIV, 1817, 510. 



