PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 15 
collection (embracing numerous specimens received since my last paper 
was written), that specimens from the patria of erythrocercus proper 
(Venezuela, Tobago, Bahia, and other parts of South America) are uni- 
formly darker colored than the smaller Mexican examples, though they 
may fully equal them in size. This darkness of color is carried to an 
extreme degree in Antillean specimens, and constitutes, so far as I am 
able to see, the sole distinguishing character of Mr. Lawrence’s “ M. 
oberi,” as compared with the continental forms of the species en masse. 
Finally, I therefore conclude that, whatever may be the character of 
Central American specimens (of course they are intermediate), or 
whether the name mexicana is to be applied to the larger or smaller race 
of the Mexican bird (and the odds are strongly in favor of the latter), 
that (1) the name erythrocercus should, if to be used at all, be restricted 
to examples agreeing strictly with the South American ‘ race,” since it 
is subsequent in date to mexicanus ; and (2) that the Rio Grande birds 
are probably exactly like the type of the latter.* 
Nyctidromus ALBICOLLIS (Gmel.) Burm.—As explained some years 
since by Dr. Sclater (see P. Z.S. 1861, p. 10, and 1866, p. 144), the earli- 
est name for this species is Caprimulgus albicollis Gmel. (S. N., I, ii, 1788, 
p. 1030), the C. americanus of Linnzus, quoted by Mr. Cassin (Proce. 
Philad. Acad. 1851, pp. 179, 180) and some other authors (see Mr. Sen- 
nett’s two lists) being unquestionably a Jamaican species belonging to 
quite a different genus (Siphonorhis americana). All the synonyms and 
the more important references are given in my notes in Dr. Merrill’s 
paper (Proc. U.S. Nat. Mus., I, pp. 143 and 144). 
IACHE latirostris (Sw.) Elliot.—This species, introduced to the fauna 
of the United States by Mr. Henshaw (cf. American Sportsman, v, Feb. 
20, 1875, p. 328; Zoology Wheeler’s Exp., Orn., p. 380) under the name of 
Circe latirostris, should be hereafter known by the above name, the 
genus Circe being previously employed in another branch of zoology 
(see Elliott, Synopsis of the Trochilidie, p. 254). 
NOMONYX, gen. nov. 
Cu.—Similar to Lrismatura, but differing from all the species of that genus in the 
form of the maxillary unguis, which is similar to that of Fulix and allied genera, the 
same being in Mrismatura the most peculiar and important generic character. 
Type, Anas dominica, Linn. 
Altogether the most distinctive feature of the genus Erismatura con- 
sists in the remarkably peculiar conformation of the maxillary unguis, 
*Tt seems proper to offer here a word of explanation in reference to the second 
paragraph on page 403 of Mr. Sennett’s paper, which says (referring to my remarks 
on this species in Dr. Merrill’s list): ‘‘There is no notice whatever of my specimen 
from Hidalgo, Tex., . . . which isin the National Museum, and which is the first record 
of its existence within our limits, and which Mr. Ridgway no doubt examined when 
he coincided with Dr. Coues as to its identification.” The explanation I have to make 
is, that at the time my paper was written and printed the specimen in question was not in 
the National Museum collection, but, with other birds, had been returned to Mr. 
Sennett, at his request, for examination. 
