EMPIDONAX. 73 
discriminate every individual. A hundred and odd specimens before us conform fairly 
to the characters of this bird as given above, but we notice slight differences in 
coloration which we believe to be due to differences of season: thus birds shot in 
Central America in early spring agree fairly well with North-American examples killed 
during the breeding-season, but autumn birds have greyer throats and more distinctly 
yellow bellies. The slightly forked tail of E. minimus seems to be the best character by 
which to distinguish it from F. frailli, and in naming our series from Mexico and Central 
America we have been governed by it rather than by measurement and slight modifica- 
tions of colour. The difference in the colour of the eggs of E. minimus, which are 
spotless buffy white, and those of L. trazl/i, which are spotted with deep rusty brown, 
at once shows that the two birds are really quite distinct. 
i. minimus enjoys a wide range throughout Eastern Mexico and Central America in 
the winter months, but it appears to be absent from Western Mexico and the central 
plateau, and only crosses to the Pacific coast at the Isthmus of Tehuantepec. In 
Guatemala it occurs on both sides of the cordillera and in the mountains up to an 
elevation of 5000 or 6000 feet. At higher altitudes in the Volcan de Fuego its place 
is taken by HL. hammond. 
ce. Subtus flavus. 
6. Empidonax flaviventris. 
Tyrannula flaviventris, W. M. & 8. F. Baird, Pr. Ac. Phil. 1843, p. 2837. 
Empidonax flaviventris, Baird, B. N. Am. p. 198°; Scl. P.Z.S. 1859, p. 366°; Cat. Birds Brit. Mus. 
xiv. p. 280*; Sel. & Salv. Ibis, 1859, p. 122°; P. Z. S. 1864, p. 360°, 1870, p. 8377; Lawr. 
Ann. Lyc. N. Y. vii. p. 8°, ix. p. 114°; Bull. U. S. Nat. Mus. no. 4, p. 27°; Sumichrast, 
Mem. Bost. Soc. N. H. i. p. 557"; Baird, Brew., & Ridgw. N. Am. B. ii. p. 378”; Salv. 
P. Z. 8. 1870, p. 199°; Coues, Birds N. W. p. 255; Key N. Am. B. ed. 2, p. 442”; 
Nutting & Ridgw. Pr. U. S. Nat. Mus. vi. p. 384°; Ridgw. Ibis, 1886, p. 466°"; Man. N. 
Am. B. p. 341 ™. 
?, Sel. P. Z. S. 1856, p. 296, no. 107”. 
Supra olivaceus; capite summo vix obscuriore; alis nigricantibus, tectricibus flavo-albido late terminatis fasciis 
duabus formantibus, secundariis internis late reliquis anguste extrorsum flavo-albido limbatis; oculorum 
ambitu pallide flavido: subtus flavus; pectore et hypochondriis olivaceo limbatis; subalaribus flavidis : 
rostri maxilla nigricante, mandibula flava; pedibus nigricantibus. Long. tota 4:5, ale 2-6, caude 2:0, 
tarsi 0°7, rostri a rictu 0°6. (Descr. maris ex Jalapa, Mexico. Mus. nostr.) 
Tyrannula 
Hab. Eastern Norto AMeErRiIca.—MeExico, Sierra Madre above Ciudad Victoria and 
Xicotencal in Tamaulipas (W. B. Richardson), State of Vera Cruz (Sumichrast 14), 
Colipa (f. D. G.), Jalapa (de Oca?, M. Trujillo), Cordova (Sallé 19), Teapa in 
Tabasco (Mrs. H. H. Smith), Guichicovi, Sta. Efigenia (Sumichrast ); G@uatEMALA 
(Skinner >), Choctum, Coban, Duefias, Retalhuleu (0. S. & F. D. G.); Honpuras, 
San Pedro (G. M. Whitely"); Nicaracua, Sucuya (Nutting 1°); Costa Rica, Ango- 
BIOL. CENTR.-AMER., Aves, Vol. IL, February 1889. 10 : 
