PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 15 



collection (embracing nnmerous 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 "ilf. 

 o&eH," 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, ifto.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 Eio Grande birds 

 are probably exactly like the type of the latter.* 



NycUdromus albicollis (Gmel.) Burm. — As explained some years 

 since by Dr. Sclater (see P. Z. S. 1861, p. 10, and 186G, p. 144), the earli- 

 est name for this species is Caprimulg us albicollis Gmel. (S. jS^., I, ii, 1788, 

 p. 1030), the C. americanus of Linnaeus, quoted by Mr. Cassin (Proc. 

 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 amcricana). All the synonyms and 

 the more important references are given in iny notes in Dr. Merrill's 

 paper (Proc. U. S. Nat. Mus., I, pp. 143 and 144). 



lACHE 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 

 Gh'ce latirostris, should be hereafter known by the above name, the 

 genus Circe being previously employed in anotlier branch of zoology 

 (see Elliott, Synopsis of the Trochilidse, p. 234). 



NOMONYX, gen. uov. 



Ch. — Similar to Erismatiira, but ditiering fi-oin 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 Erismatiira the most peculiar and important generic character. 



Type, Anas domiiiica, Linn. 



Altogether the most distinctive feature of the genus Erismatiira con- 

 sists in the remarkably peculiar conformation of the maxillary unguis, 



* It seems proper to offer here a word of explanation in reference to the second 

 paragraph on page 40:5 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 is in 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. Cones as to its identihcation." The explanation I have to make 

 is, that at the time m>i paper was written and printed t\\c. specimen in question was not in 

 the National Museum collection, but, with other birds, had been retiunied to Mr. 

 Seunett, at his request, for examination. ' 



