46 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



Bill much shorter than head, rather broad basally, compressed 

 and strongly but gradually decurved terminally, its width at anterior 

 end of nostrils decidedly less to much less than its depth at same point ; 

 exposed culmen equal to or longer than outer anterior toe without 

 claw (longer than toe with claw in P. melanogastra), strongly decurved 

 from near base, rather narrowly rounded; gonys decidedly longer 

 than mandibular rami, nearly straight but usually very faintly concave 

 terminally, slightly prominent basally, narrowly rounded or very indis- 

 tinctly ridged; maxillary tomium distinctly concave to beneath or 

 posterior to nostril, deflected and more or less convex basally, without 

 trace of subterminal notch. Nostril obliquely longitudinal, narrowly 

 elliptical, in lower anterior portion of nasal fossa. . Wing rather short, 

 strongly rounded, the longest primaries exceeding distal secondaries by 

 not more (usually muchless) than length of exposed culmen; fifth and 

 sixth or fourth to sixth primaries longest, the eighth about equal to 

 distal secondaries, the tenth (outermost) half as long as longest 

 primary or a little more. Tail much more than one and a half times 

 (sometimes more than twice) as long as wing, graduated for much 

 more than one-third (sometimes for one-half) its length, the rectrices 

 ■ relatively rather broad; tarsus about one and a half times as long as 

 middle toe without claw, about one-fourth as long as wing. 



Plumage and coloration. — Orbital region mostly naked (brightly 

 colored in life); eyelashes strongly developed; no trace of bristles 

 about base of bill; plumage in general soft and blended, somewhat 

 hair-like, especially on head, neck, and under parts; pileum not 

 crested. General color bright cinnamon-rufous to chestnut, paler on 

 throat and chest, the pileum sometimes gray; under parts of body 

 light bluish gray to dusky; rectrices broadly tipped with white and 

 with a more or less distinct broad subterminal band or area of black. 



Range. — The whole of Tropical America t except West Indies and 

 Galapagos Islands. (About twelve species and subspecies.) 



KEY TO THE SPECIES AND SUBSPECIES OF PIATA. a 



a. Under side of rectrices (except white tips) black (sometimes with concealed portion 

 more or less tinged with rufescent brown); upper parts chestnut or bay; under 

 parts of body deeper gray. (P. cayana.) 



o Including among extralimital forms only the true P. cayana and those occurring 

 in Colombia. The South American forms have been worked out, more or less satis- 

 factorily, by Cabanis (Mus. Hein., iv, Heft 1, 1862, 82-88); J. A. Allen (Bull. Am. 

 Mus. N. H., v, 1893, 136-139); Hellmayr (Novit. Zool., xiii, 1906, 43, 44); Stone 

 (Proc. Ac. Nat. Sci. Phila., 1908, 492-501), Dabbene (Orn. Argentina, 1910, 423-427, 

 footnotes), and Cory (Pub. 183, Field Mus. Nat. Hist., Orn. Ser., i, no. 9, Aug. 7, , 

 1915, 304, 307-310). Among the considerable number of more or less strongly marked 

 South American forms are the two styles of coloration represented in Middle America 

 by P. c. ihermophila and P. mexicana, respectively, and these certainly represent two 

 specific types; certainly it is impossible that P. c. thermophila and P. memcana can be 

 conspecific, for perfectly typical examples of each- occur together in the State of 

 Oaxaca, and none of the large number of specimens examined shows the slightest inter- 

 gradation of characters. 



