BIRDS OF NORTH AND MIDDLE AMEBIC A. 257 



have resulted in failure, and consequently I am forced, against my 

 inclination, to include a rather heterogeneous assemblage of species 

 under one generic heading. Possibly a study of their internal struc- 

 ture may afford characters for subdivision. 



Of all the species I. icterus seems to differ most structurally, this 

 alone having a large naked postocular space and the feathers of the 

 throat elongated and acicular; but that species is evidenly related to 

 /. jomiacaii and I. oroconotus, both of which are normal in the respects 

 mentioned (though both, especially the former, have the feathers of 

 the lower throat distinctly outlined and somewhat lengthened), have 

 the tail relatively longer and much more graduated, and the tarsus 

 relatively longer, thus apparently connecting I. icterus with other 

 types of structure. 



KEY TO THE SPECIES AND SUBSPECIES OF ICTERUS. 



a. Tail entirely black (except concealed base'), or else distinctly bicolored (black 

 and yellow or black and orange in sharply contrasted areas). 

 b. Tail unicolored (black, except at concealed base'), 

 c. Feathers of throat elongated, lanceolate or acicular, somewhat stiffened; cul- 

 men more than 1.25. (Caribbean coast of Colombia and Venezuela; islands 

 of Trinidad, Jamaica, Porto Rico, and St. Thomas. ) 



Icterus icterus, adult male and female p. 263) 

 cc. Feathers of throat normal (short and blended); culmen less than 1.25. 

 d. Head, all round, uniform black or chestnut. 

 e. Back and scapulars uniform black. 

 /Under parts of body and rump neither chestnut nor rufous-tawny. 

 g. Lesser and middle wing-coverts black, like rest of wing. (Island of 

 Montserrat, Lesser Antilles. ) 



Icterus oberi, adult male and female (p. 265) 

 gg. Lesser and middle wing-coverts yellow or orange. 

 h. Wings with white markings. (Pacific coast of Guatemala.) 



Icterus maculi-alatus, adult male and female (p. 265) 

 hh. Wings without white markings. 

 j. Breast yellow or orange. 



h Tail-coverts yellow; smaller (wing 92.2-99.1). (Bahamas.) 



Icterus northropi, adult male and female (p. 266) 



kh. Tail-coverts black; larger (wing 96.5-113.8). (Mexico; 



Guatemala. ). Icterus wagleri, adult male andfemale(p.267) 



jj. Breast black. 



k. Posterior half, or more, of under parts yellow. (Southern 

 Mexico to Isthmus of Panama. ) 



Icterus prosthemelas, adult male and female (p. 269) 

 kk. Less than posterior half of under parts yellow (or orange) . 

 I. Rump, lesser and middle wing-coverts, thighs, etc., lemon 

 yellow; under tail-coverts and flanks partly black, 

 m. Abdomen and flanks wholly black; under tail-coverts 

 mostly black. (Island of Cuba, Greater Antilles.) 

 Icterus hypomelas, adult male and female (p. 271) 

 mm. Abdomen or flanks partly yellow; under tail-coverts 

 mostly yellow. 



'There is sometimes a whitish tip or termmal margin, especially to the lateral rec- 

 triees, these being worn away in summer plumage, 

 3654— VOL 2—01 17 



