212 TROCH1LUS COLUBRIS. 



ORDER V. TROCHILI. HUMMING BIRDS. 



Sternum, with no marginal indentations but with the posterior border much rounded. Keel, 

 very high. Bill, very long, with a wide and deep gape, but there are no bristles at the base. 

 The plumage is compact. 



One of the most remarkable characters in this group is the exceedingly long tongue 

 which is thin, bifid and the edges are curved so as to form a tube, while the hyoid bones 

 curve back of the skull as in the Woodpeckers. The bill is awl-shaped, sometimes straight, 

 at others, curved or even recurved; it also varies greatly in length and is rarely shorter 

 than the head but is often elongated. All the members of this family are small, yet there 

 is much variation in this respect, some of the species being so minute that they are exceed- 

 ed by many insects in size. In variety of plumage, they are not excelled by any other 

 class of birds, while in hue, they also rival all others, being the gems among the feathered 

 tribe. They are restricted in distribution to the Continent of America and adjacent islands 

 but although several occur west of the Central Plain, only one species comes into the range 

 of which I write. It will be observed that I have placed these birds in a separate order 

 from the Swifts which they resemble somewhat but it appears to me that, as they differ in 

 many respects, they should consistently take rank as an Order. 



FAMILY I. TROCHILID^l. THE FORK-TAILED HUMMING BIRDS. 



Tip of mandibles, without any distinct serrations. Throat, with iridescent, scale-likt 

 feathers. 



The form of the tail is different in the female and young male from that of the adult 

 male, being rounded in the two former, and the throat is not as brilliant. 



GENUS I. TROCHILUS. THE GREEN-BACKED HUMMERS. 



GEN. On. Sternum, very narrow anteriorly, with exceedingly short coracoids. The heart is remarkably large, being 

 equal to one half the length of the sternum. 



The colors are green above and white below and the male has a gorget of metallic-like feathers on the throat. Both 

 the heart and liver are remarkably large, the latter extending over the whole abdomen, completely covering the intestines. 

 The trachea is peculiar as the inferior larynx is placed high, consequently the bronchial tubes are very long. The only 

 laryngeal muscle that I ever detected is a large one that completely encloses the larynx. There is no tympaniform mem- 

 brane. The stomach is not muscular. The wing bones are as given in the Swifts and the pectoral muscles are exceedingly 

 well developed, and as in that group, the legs are placed high. 



THOCHILUS COLUBKIS. 



Buby-throated Humming Bird. 



Trochilus colubris LINN., Syst. Nat., I; 1766, 191. 



DESCRIPTION. 



SP. Cn. Form, rather robust. Size, medium. Sternum, stout. Tongue, bifid for its terminal third, and very thin at 

 the tip but there is no cilia. Bill, a little longer than the head. 



COLOR. Adult male. Uniform metallic-like green above. Beneath, white, with the throat ruby-red with a metallic 

 luster; the sides and flanks are greenish. The wings are brown glossed with violet. The tail is greenish at the base, 

 excepting outer feathers, the remainder is like the wings. There is an indistinct white spot back of the eye. 



