\^^ 



112 HIRUNDINID^, SWALLOWS. GEN. 43. 



are not very tangible, and there is little probability of their proving constant. 



Though the difference in the shape of the bill of the tj-pe specimens is evident (fig. 



52, a and &), yet this is no more than that oc- 

 curring in Eastern specimens of unquestionable 

 cestiva. (See Plate ii, flgs. 19, 20, a, b.) It 

 may, however, take rank as a geographical variety. 



&^ '^ ~- <(^ Hepatic Tanager. Ashy -red, or liver- 



* \ browu, brighter red on the head and under 



parts ; sides ashy-shaded ; bill plumbeous 



FIG. 63. Hepatic Tanager. black, consplcuously toothcd ; ? like that of 



the foregoing, but ashier on the back. Size of the last. New Mexico, 



Arizona, and southward. Bd., 302; Eidgway, Proc. Acad. Phila. 1869, 



132; Coop., 144 hepatica. 



Louisiana Tanager. ^ bright yellow, middle of back, wings, and tail, 

 black ; head crimson ; Avings with two yellow bars. ? most nearly resem- 

 bling that of rubra, but distinguished from this or any of the foregoing by 

 presence of two whitish or greenish-yellow wiug-ljars, and much edging of 

 the same color on the inner quills. Immature $ shows the black of the 

 back mixed with olive, and the head only tinged with red ; at first it is like 

 the 5 . Size of the first species. IT. S., Rocky Mountains to the Pacific 

 (not in Louisiana !). Wils., iii, 27, pi. 20, f. 1 ; Nutt., i, 471 ; Aud., iii, 

 231, pi. 210; Bd., 303; Coop., 145 lubovigiana. 



Family HIRUNDINIDiE. Swallows, 



Fissirostral Oscines. Bill short, broad, flat, deeply cleft, the gape wide and 

 about twice as long as the culmen — it generally reaches to about opposite the 

 eyes. Nasal fossa3 short, broad, the nostrils directed more or less upward, some- 

 times circular and completely open, sometimes overhung by a straight flat scale. 

 Rictus with a few inconspicuous bristles or none. Wings extremely long, of nine 

 primaries, of which the first equals or exceeds the second, the rest being rapidly 

 graduated, the ninth hardly or not half as long as the first ; secondaries and their 

 coverts extremely short. Tail of 12 (rarely 10?) rectrices, usually forked, some- 

 times forficate with filamentous outer feathers. Feet short and weak ; tarsi 

 scutellate (occasionally feathered), commonly shorter than even the lateral toes; 

 basal joint of middle toe adherent to one or both lateral toes ; toes with the normal 

 number of phalanges. 



This is a perfectly natural group, well distinguished by the foregoing characters. 

 The swallows alone represent, among Oscines, the fissirostral tj'pe of structure ; 

 they have a close superficial resemblance to the swifts and goat-suckers of another 

 order, but the relation is one of analog}', not of afflnit}', though all these birds 

 were formerly classed together in the highly unnatural " order" Fissirostres. (See 

 beyond, under Cypselidce and CaprimulgidcB.) 



A hundred species of swallows are recorded ; probably about three-fourths of 

 them are genuine. Thej' are distributed all over the world ; the most generalized 

 types, like Hirundo itself, are more or less cosmopolitan, but each of the great 

 divisions of the globe has its peculiar subgenera or particular sets of species. Thus, 

 all the American groups except Ilinuido and Cotyle are peculiar to this continent. 



