TROCHILID.E THE HUMMINGBIRDS. 361 



mountainous portions of the southwestern United States, including 

 the semi-tropical Eio Grande valley. Small as this number may 

 appear, the southwestern portion of the Union may be considered 

 richly represented when compared with the vast valley of the Mis- 

 sissippi and the Atlantic water-shed a region of unsurpassed fer- 

 tility and luxuriant vegetation, yet which throughout its whole extent, 

 even including the peninsula of Florida, possesses only a single 

 species. In this scarcity, compared with the western mountainous 

 regions, of representatives of a numerous family of birds, we see a 

 certain parallelism with the lowlands of eastern South America as 

 compared with the Andean highlands, only, on account of climatic 

 differences, the contrast is more marked. 



We have therefore to consider but a single genus or species of 

 Hummingbird in the present work, none of the western species 

 coming sufficiently near to render their occurrence in the least prob- 

 able. 



GENUS TROCHILUS LINNAEUS. 



TrocJiilus LINN.EUS, Systema Natura. ed. 10. i, 1758, 119. Type (by elimination) T. colu- 

 bris LIOTT. 



GEN. CHAK. Male with the metallic gorget of the throat nearly even all round. Tail 

 forked; the feathers lanceolate, acute, becoming gradually narrower from the central to 

 the exterior. Inner six primaries abruptly and considerably smaller than the outer 

 four, and with the inner web notched at the end. 



The female has the outer tail-feathers somewhat lanceolate, as 

 in the male, though much broader. They are broad to the terminal 

 third, where they become rapidly pointed, the tip only somewhat 

 rounded ; the sides of this attenuated portion (one or the other, or 

 both) broadly and concavely emarginated, which distinguishes them 

 from the females of Selasphorus and Calypte, in which the tail- 

 feathers are broadly linear to near the end, which is much rounder 

 and without any distinct concavity. 



Trochilus colubris Linn. 



EUBY-THEOATED HUMMINGBIRD. 



Trochilus colubris LINN. S. N. ed. 10, i.1758, 120. WILS. Am. Orn. ii, 1810. 26, pi. 10, (\< t 

 3,4. NUTT. Man. i, 1832 588. AUD. Orn. Biog. i, 1832, 248; v 1839, 544, pi. 47 ; Synop. 1839, 

 170; B. Am. iv. 1842, 190, pi. 253. BAIKD, B. N. Am. 1858 131; Cat. N. Am. B. 1859, No. 

 101. COUES, Key, 1872, 184; Check List, 1874, No. 275; 2d ed. 1882, No. 410; B. N. W. 

 1874, 271. B. B. & R. Hist. N. Am. B. ii, 1874. 448, pi. 48. fig. 2. RIDGW. Norn. N. Am. 

 B. 1881, No. 335. 



