PASSEKES. 

 Fam. HIRUND1NID.E *. 

 Bill short, very broad at the base, triangular when viewed from above; flattened, straight, 

 the culmen gently curved at the tip, which is entire; gape smooth and very wide. Wings long 

 and pointed, the first two quills longer than the third ; the secondaries very short. Tail of 12 

 feathers, variable in shape and length. Legs and feet weak; tarsus short, generally bare, and 

 covered with smooth scales, in some feathered. 



Genus HIBTJXDO. 

 Bill typical in shape, compressed near the tip. The nostrils basal, elongated and exposed, 

 placed in a depression near the culmen. Wings with the 1st quill equal to or longer than the 

 2nd. Tail long and deeply forked. Tarsus equal to the middle toe, and shielded in front with 

 smooth broad scutes. Middle toe much longer than the lateral ones, which are subequal ; hind 

 toe moderately large. 



HIBUNDO EUSTICA. 



(THE COMMON SWALLOW.) 



Hirmdo rustica, Linn. Syst. Nat. i. p. 343 (1766) ; Blyth, Cat. Mus. A. S. B. p. 197 (1849) ; 



Jerdon, B. of Inch i. p. 157 (1862) ; Sharpe & Dresser, P. Z. S. 1870, p. 244 ; Holdsw. 



P. Z. S. 1872, p. 418; Shelley, B. of Egypt, p. 120 (1872) ; Hume, Nests and Eggs, i. 



p. 72 (1873) ; id. Str. Feath, 1874, p. 154 (Andamans); Salvadori,Ucc. Born. p. 125 (1874); 



Dresser, B. of Europe, pt. 39 (1875) ; Irby, B. of Gibraltar, p. 103 (1875) ; Legge, Ibis. 



1875, p. 275. 

 Eirunclo panayana, Gmel. Syst. Nat. i. p. 1018 (1788) ; Horsf. & Moore, Cat. B. Mus. E. I. 



Co. i. p. 91 (1854). 

 Hirundo gutturalis, Scop. Delic. Flor. et Faun. Insubr. ii. p. 96 (1786); Kelaart, Prodromus, 



Cat. p. 118 (1852) ; Layard, Ann. & Mag. Nat. Hist. 1853, xii. p. 170 ; Swinhoe, P. Z. S. 



1871, p. 346. 



* The Swallows are classed by Jerdon and other naturalists (Van der Hoeven, Kaup, &e.) with the Swifts : aud, on 

 account of their outward similarity to them, it is the popular belief that the two families are closely allied. Ko greater 

 error, I think, could exist, although, as Mr. Wallace pithily remarks in a letter to me on the subject, " they constitute the tnost 

 remarkable case Icnoivn of outward resemblance and real diversity." The Swallow, in the formation of its sternum, legs, aud 

 foot, and in the structure of its wing, as also in the number of the tail-feathers, is strictly a Passerine bird. The Swift i> 

 a Picariform bird in its sternum and foot, which latter is most remarkable, all the toes being either directed forward, or 

 the hind toe being reversible to the front. The bill is unlike that of a Swallow, resembling those of the Nightjars. Blyth, 

 Huxley, and others hold the Swallow to be Passerine in all respects ; the former, who took strong exception to what he styled 

 Jerdon's antiquated notion of associating the two families, remarks (Ibis, 1866, p. 230): — "The Hirundinidre illustral 

 and exemplify, even to the minutest detail, the special passerine type of conformation, which is merely modified ex- 

 ternally to confer extraordinary vigour of wing."' The hind toe, in some of the Sand-Martins, is said to have a tendency 

 to reverse ; this feature is not exemplified in the case of the two English species. 



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