326 EEPORT OF NATIONAL MUSEUM, 1890. 



Generic characters. — Male with the metallic gorget not elon- 

 gated laterally. Tail forked or deeply etnarginate, the feath ers pointed, 

 but the exterior ones not excessively narrow. Six inner primaries 

 abruptly and conspicuously smaller tban the rest, with their inner web 

 more or less notched and toothed at the tip (except iu T. violajugulum). 



The peculiarity above noted iu the reduced size and modified form of 

 the six inner primaries is most marked in T. colubris, and may be more 

 particularly described as follows: . The outer four prim aries are of the 

 usual shape, and diminish gradually in size 5 the remaining six, how- 

 ever, are abruptly much smaller, more linear, and nearly equal in width 

 (about that of inner web of the fourth), so that the interval between 

 the fifth and fourth is from two to five times as great as that between 

 the fifth and sixth. The inner web of these reduced primaries is also 

 emarginated at the end. This character is even sometimes seen in the 

 females, but to a less extent, aud may serve to distinguish both colu- 

 bris and alexandri from other allied species where other marks are ob- 

 scured. 



In T. violajuguium the inner primaries are not ob viously abnormal 

 either in size or shape, there being, as is usually the case in Humming 

 Birds, a gradual decrease in size from the outer quill. A very close 

 inspection, however, will show that while the distinct emargination at 

 the tip of the inner web of these remiges in T. colubris and T. alex- 

 andri is wanting, there is an indication of the tooth-like projection just 

 anterior to the end of the web. In fact, T. alexan dri is very nearly in- 

 termediate in this respect between T. violajugulum and T. colubris, though 

 nearest the latter. 



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 somewhat rounded; the 

 sides of this attenuated portion (one or other, or both) broadly and 

 concavely emarginated, which distinguishes them from the females of 

 Selasphorus and Galypte, in which the feathers are broadly linear to near 

 the end, which is much rounder and without any distinct concavity. 



The genus Trochilus, as here restricted, includes three species, all 

 belonging strictly to North America, though like many other Nearctic 

 birds they winter chiefly within the tropics. One is eastern, the other 

 two western, in distribution, one of the latter being, so far as known, 

 very local in its range. 



The three species agree in the following characters of coloration : 

 Upper parts, including top of head, metallic greenish, varying from 

 nearly pure green to bronzy; median lower parts whitish, the sides 

 metallic green; adult males with a portion of the gorget brilliantly 

 metallic red, rose-purple or violet, the anterior portion velvety black ; 

 tail-feathers (except middle pair) uniform purplish black. Adult females 

 and young with chin and throat dull whitish, or pale grayish (some- 

 times spotted centrally with the metallic color of the male), the rec- 



