922 
U. S. P. R. R EXP. AND SURVEYS—ZOOLOGY—GENERAL REPORT. 
the new species, which doubtless replaces P. varius. It is probably resident about Fort Bridger, 
specimens having been obtained in June. 
Lampornis mango, Sw., p. 130.—Mr. Sclater thinks that if any Lampornis occurs in Florida, 
it is most probably L. porpliyrula, found in Jamaica, the L. mango belonging more to South 
America. The specimen described, however, is from Brazil, and a true L. mango. 
Selasphorus platycercus, Gould, p. 135.—Numerous specimens of this species have lately 
been received from Cantonment Burgwyn, N. M. (Dr. W. W. Anderson), and Fort Bridger, 
showing it to be a common bird of the Rocky mountains, and probably ranging far north. The 
female lacks the red throat and the green of the sides, which, with the crissum, are tinged with 
reddish, as in S. rufus , from which it differs in the absence of this color on the bases of the 
rump feathers. The tail is rounded, the lateral feathers wider than in S. rufus , broadly tipped 
with white. All are strongly edged and tinged towards the base with brownish red, less 
conspicuously than in S. rufus. 
Nephoecetes Niger, Baird, p. 142.—Additional specimens of this species were collected in the 
spring of 1858, at Simiahmoo bay, where it was found by Dr. Kennerly to be quite abundant. 
Chordeiles iienryi, Cassin, p. 153.—A large collection of Ghordeiles (about 50 specimens) 
made at Fort Bridger by Mr. Drexler, shows constant differences from eastern specimens, 
entitling the Rocky mountain bird probably to specific rank. It is much lighter, greyer, and 
more generally mottled above, the back and scapulars varied with pale rufous. The white 
patch on the wing is nearer the carpus. The under parts are lighter, the black bars narrower. 
The greater under wing coverts are conspicuously instead of obsoletely barred with whitish. 
Milvulus tyrannus, Bon. p. 168.—According to Mr. Sclater this species reaches as far north 
as Yera Cruz. 
Tyrannus vociferans, Sw., p. 174.—West of Fort Laramie. C. Drexler. 
Empidonax obscurus, Baird, p. 200.—Many specimens.of this species were collected at Fort 
Bridger by Mr. Drexler. Some of these are more ashy above and less olivaceous than in 7234, 
the whitish bands on wing narrower, and very little yellowish beneath. There appear to be 
two types among Mr. Drexler’s specimens, one with the bill longer, straighter on the edges, 
and with the lower mandible yellow, only tipped with black, instead of being uniformly 
brownish. I have not, however, time at present to pursue the investigation further for the 
purpose of ascertaining whether there are really two species. 
The species was also found at Fort Yuma by Lt. Ives’s expedition. 
? Turdus sirens, Sw., p. 213.—In a series of thrushes referable to T. nanus , collected at 
Fort Bridger by Mr. Drexler, is a specimen much larger than the rest, or even than T. 
pallasii , and agreeing more nearly with No. 7950, considered identical with T. silens of 
Swainson. The length is 7^ inches ; the wing 4.25 ; the tail 3.60 ; the tarsus 1.30. The type 
of coloration is that of T. nanus , in a more olivaceous green of the upper parts anteriorly 
than in T. pallasii. 
Turdus fuscescens, Steph., p. 214.—Specimens from Fort Bridger have the spots a little 
darker than in Carlisle skins, but scarcely enough so to have them referable to T. ustulatus. 
Sialia. —Mr. Sclater has a new species from Guatemala, S. albiventris. 
Hydrobata mexicana, Baird, p. 229.—Fort Tejon. J. Xantus de Vesey. 
Parula mexicana, Bon., p. 237.—Mr. Sclater writes that the oldest name of this species is 
superciliosa. ( Conirostrum superciliosum, Hartlaub.) 
Aegithina leucoptera, Vieill., p. 305.—According to Mr. Sclater, this is an Iora from East 
Indies ; probably I. scapularis. 
