BIRDS OF NORTH AND MIDDLE AMERICA. 407 
the group of species composing the three so-called genera here tenta- 
tively recognized constitute a very difficult problem, for, apparently, 
no matter whether they are combined into a single genus or divided 
into several the definition of the group or groups is equally difficult in 
either case. 
KEY TO THE SPECIES AND SUBSPECIES OF AMIZILIS. 
a. Chin and throat not white. 
b. Throat and chest metallic green. 
c. Breast and abdomen not white. 
d. Lores chestnut; sides, anterior flanks, and under wing-coverts uniform 
metallic green or bronze-green; abdomen grayish (sometimes tinged with 
buffy). (Amizilis tzacatl.) 
e. Abdomen brownish-gray. (Andes of Ecuadér and Venezuela through 
Colombia to southeastern Mexico.).-... Amizilis tzacatl tzacatl (p. 408). 
ee. Abdomen decidedly buffy grayish (much paler in females). (Western 
Ecuadér and southwestern Colombia.) 
Amizilis tzacatl jucunda (extralimital).¢ 
dd. Lores not chestnut; sides, anterior flanks, and under wing-coverts at least 
partly cinnamon-rufous or cinnamon-buff. (Amizilis yucatanensis.) 
e. Under parts of body deeper cinnamon-rufous, the sides without mixture 
of metallic bronze or bronze-green. (Tabasco, Campeche, Yucatan, and 
British Honduras.)........ Amizilis yucatanensis yucatanensis (p. 412). 
ec. Under parts paler cinnamon-rufous or cinnamon-buff, the sides glossed 
or intermixed with greenish bronze or bronze-green. 
f. Under parts of body light cinnamon-rufous or vinaceous-cinnamon; 
upper parts more greenish bronze. (States of Vera Cruz, Puebla, 
Oaxaca, and Chiapas.)..Amizilis yucatanensis cerviniventris (p. 414). 
J. Under parts of body light cinnamon-buff to pale pinkish buff; upper 
parts more bronzy. (Southern Mexico, Tamaulipas, and Nuevo 
Leén.)....---.-.------- Amizilis yucatanensis chalconota (p. 415). 
cc. Breast and abdomen white; tail glossed with metallic purple. (Western 
MEXICO) csciit J. esol ei cuosaeet navies wey danas Amizilis forreri (p. 416). 
bb. Throat and chest cinnamon-rufous (more or less deep), like rest of under parts. 
c. Sides of neck cinnamon-rufous. 
d. Smaller (wing 51-60, tail 31-37, culmen 19.5-23.5).  (Amizilis rutila.) 
e. Coloration pale, the under parts vinaceous-rufous or light cinnamon-rufous. 
(State of Sinaloa, western Mexico, to Yucatan and eastern Guatemala 
and thence to western Costa Rica.)...... Amizilis rutila rutila (p. 416). 
ee. Coloration darker, the under parts deep cinnamon-rufous. (Pacific slope 
of Chiapas and Guatemala.)...... Amizilis rutila corallirostris (p. 419). 
dd. Larger (wing 66-69.5, tail 4245.5, culmen 23.5-27). (Tres Marias Islands, 
western Mexico.)..........-..2-----+--+++---- Amizilis graysoni (p. 419). 
cc. Sides of neck metallic greenish bronze. (Northwestern Costa Rica.) 
Amizilis bangsi (p. 420). 
@ E[ranna] jucunda Heine, Journ. fiir Orn., 1863, 188 (Babahoyo and Esmeraldas, 
w. Ecuador; coll. Heine Mus.).—[Ariana riefferi] var. jucunda Mulsant, Ann. Soc. 
Linn. Lyon, xxii, 1876, 206.—Amazilia riefferi jucunda Berlepsch and Taczanowski, 
Proc. Zool. Soc. Lond., 1883, 568 (Chimbo, w. Ecuadér); 1884, 306 (Cayandeléd and 
Pinampunga, w. Ecuadér).—Amazilia fuscicaudata jucunda Hartert, Novit. Zool., v, 
1898, 496 (Chimbo; habits).—A[mazilia] fuscicaudata jucunda Hartert, Das Tierreich, 
Troch., 1900, 58.—Amizilis tzacatl jucunda Oberholser, Proc. U. 8. Nat. Mus., xxiv, 
no. 1258, Jan., 1902, 317 (Santo Domingo, w. Ecuador). 
