BIRDS OF NORTH AND MIDDLE AMERICA, 549 



ee. Larger, with relatively larger bill and shorter and less deeply forked tail, 

 the lateral rectrices broader terininally; wing, 47-50.5, tail, 39-44, 

 middle rectrices, 16-18.5, culmen, 14-15.5. (Oozumel Island, Yuca- 

 tan.) Chlorostilbou forficatus, adult male (p. 552). 



dd. Tail uuich shorter than wing. {Chlorostilbon caiiivetU.) 



e. Tail longer and more deeply forked, the middle rectrices always distinctly 

 tipped with gray; tail averaging 34.6, middle rectrices averaging 18.1. 

 (Southeastern Mexico, including Yucatan, to Ikitish Honduras.) 



Chlorostilbon canivetii canivetii, adult male (p. 553). 



ee. Tail shorter and less deeply forked, the middle rectrices less distinctly 



(sometimes obsoletely) tipped with gray; tail averaging less than 32, 



middle rectrices averaging more than 18.5. 



/. Maxilla more extensively brownish (or reddish) basally, never wholly 



blackish; middle rectrices usually with gray tip distinct; tail averaging 



longer and more deeply forked; wing averaging 45.8, tail 31.1, middle 



rectrices 18.6. (Guatemala, Honduras, and Salvador.) 



Chlorostilbon canivetii osberti, adult male (p. 556). 



ff. Maxilla less extensively brownish (or reddish) basally, sometimes wholly 



blackish; middle rectrices usually with gray tip indistinct, sometimes 



obsolete; tail averaging shorter and less deeply forked; wing averaging 



46, tail 27.9, middle rectrices 19.2. (Nicaragua and Costa Rica.) 



Chlorostilbon canivetii salvini, adult male (p. 557). 

 cc. Maxilla wholly black; middle rectrices without trace of gray tip. 

 d. Mandible pale (pink or reddish in life) basally; tail 32.5-38.5. (Porto Rico.) 



Chlorostilbon maugaei, adult male (p. 550). 

 dd. Mandible wholly black, like maxilla; tail 25.5-30. (Coast of Venezuela 

 and islands of Trinidad, Margarita, Aruba, Bonaire, and Curasao.) 



Chlorostilbon caribaeus, adult male (p. 559). 

 hh. Forehead and crown dull metallic green, like back, etc. (Bill wholly black; 

 wing averaging 45.6, tail 27.8, middle rectrices 19.4.) (Panama and south- 

 western Costa Rica.) Chlorostilbon assimilis, adult male (p. 558). 



aa. Under parts pale gray. [Adult females.) 



b. Outermost rectrix with a band of gray across middle portion. 

 c. Whitish postocular streak minute; mandible wholly dusky; lateral rectrices 

 narrower, with basal area of dusky not well-defined. 



Chlorostilbon maugaei, adult female (p. 550). 

 cc. Whitish postocular streak conspicuous; mandible extensively pale basally; 

 lateral rectrices broader, with basal dusky area well-defined. 

 d. Tail averaging more than 31. 



e. Culmen 13-15.5 (14.2), tail 30-33.5 (31.7), the lateral rectrices narrower 



(about 4 mm.) Chlorostilbon auriceps, adult female (p. 551). 



ee. Culmen 15.5-16.5 (15.8), tail 31-35 (32.8), the lateral rectrices broader 



(about 5-5.5 mm.) Chlorostilbon forficatus, adult female (p. 553). 



dd. Tail averaging less than 30. 

 e. Tail averaging more than 29, the middle rectrices averaging less than 22. 

 Chlorostilbon canivetii canivetii, adult female (p. 554). 

 ee. Tail averaging less than 28, the middle rectrices averaging more than 22. 

 /. Tail 27.5, the middle rectrices 23. 



Chlorostilbon canivetii osberti, adult female (p. 556). 

 ff. Tail 25-28 (26.6), the middle rectrices 21-24 (22. 7). a 



Chlorostilbon canivetii salvini, adult female (p. 557). 

 bb. Outermost rectrix without any gray band across middle portion. 



c. Culmen 13-15.5 (14.3) Chlorostilbon assimilis, adult female (p. 558). 



cc. Culmen 16.5-17 (16.7) Chlorostilbon caribaeus, adult female (p. 560). 



a The series of adult females of the different forms of C. canivetii is too small, espe- 

 cially of C. c. osberti and C. c. salvini to admit of their satisfactory differentiation. 



