848 BULLETIN 50;, UNITED STATES NATIONAL MUSEUM. 



d. Abbreviated and concealed ninth (next to outermost) primary broader 

 (5-G mm.); black of pileum more intense, more glossy. « (Platypsaris 

 aglaix.) 

 e. Back slate color or elate-gray, distinctly different from and abruptly con- 

 ■ trasted with black of pileum and nape. 

 /. Lower throat with a large patch of rosy red or geranium pink. 



y. Back slate color; under parts distinctly gray, the chin and upper 

 throat usually pale gray. 

 h. Larger (wing averaging 94.8, tail, 70.6). (Northeastern Mexico to 

 southern Texas.). ..Platypsaris aglaiae aglaise, adult male (p. 850) 

 7(7*. Smaller (wing averaging less than 88, tail less than 66 mm.). 

 i. Slightly larger with relatively much larger bill (wing averaging 

 87.2, tail 65.6, exposed culmen, 17.2, tarsus 21.1). (Yucatan.) 

 Platypsaris aglaiae yucatanensis, adult male (p. 858) 

 ii. Slightly smaller, with relatively much smaller bill (wing averag- 

 ing 85.7, tail 64.5, exposed culmen 14, tarsus 20.2). Tres Marias 

 Islands, western ]\Iexico.) 



Platypsaris aglaiae insularis, adult male (p. 857) 

 gg. Back slate-gray or ash-gray; under parts very pale gray, sometimes 

 mostly white, the chin and upper throat pure white. Pacific slope 

 of Mexico, north to southern Arizona.) 



Platypsaris aglaiae albiventris, adult male (p. 856) 

 ff. Throat wholly slate-gray, or else a small patch of pale orange-red or flesh 

 color on lower portion. (Pacific slojje of Central America.) 



Platypsaris aglaiae latirostris, adult male (p. 855) 



ee. Back black (glossy l)lack to slate-black), not distinctly if at all contrasted 



with color of pileum and nape. 



/. Slightly larger (wing averaging 88.8, tail 66.1, exposed culmen 16.3, 



tarsus 21.4); lower throat with a purplish red patch. (Southeastern 



Mexico to Guatemala.) 



Platypsaris aglaiae sumichrasti, adult male (p. 852) 

 ff. Slightly smaller (wing averaging 87.5, tail 61.6, exposed culmen 15.4); 

 whole throat slate color or slate-gray or (rarely) with onlj/ a trace of 

 purplish red. (Southern Guatemala to Costa Rica.) 



Platypsaris aglaiae hypophaeus (j). 854) 

 dd. Abbreviated and concealed ninth primary narrower (4.5-5 mm.); black of 

 pileum duller. (Otherwise apjjarently indistinguishable from adult 

 male of P. aglaac latirostris!) (Panama to Peru.) 



Platypsaris homochrous, adult male (p. 859) 

 aa. Back and rump grayish brown to rufous-tawny or tawny-chestnut. (Adult 

 female and young.) 

 b. Pileum and nape different in color fronr l)ack and rump. 

 c. Pileum sepia or umber brown; larger (wing 97-106). 



Platypsaris niger, adult female and young (pp. 849, 850) 

 cc. Pileum blackish or gray; smaller (wing 80-98). 



Platypsaris aglaiae (and subspecies), adult female and young. 

 Platypsaris atricapillus, adult female and young. ^ 



« Having only two adult males of P . homochrous I am not sure that these -characters 

 will hold good in a larger series. Considering the conspicuous difference in coloration 

 l)etween the adult females of this'form and those of all the forms of P. aglaise, the two 

 must be specifically distinct; yet I am unable to find more tangil)le characters for 

 separating the adult male of P. a. latirostris from that of P. homochrous ! 



b I must confess my inability, at present, to construct a key which shall define satis- 

 factorily the characters of the adult females and young of the several subspecies of 



