BIRDS OF NORTH AND MIDDLE AMERICA. 653 



Genus GEOTHLYPIS Cabanis. 



TricJtas (not of Gloger, 1S27) .Swainson, Zool. Journ., iii, 1.S27, 167. (Type, 



T. persoiKitus Swainson, =T'»r(/tts tridia.'i Linnteus. ) 

 Geothlypis^ Cabanis, Wiegmann's Archiv. fiir Naturg., 1847, i, 316, 349. (Type, 



Turdufi Irlchas Linn;eus. ) 



Riithcr small terrestrial Mniotiltidtv with the middle toe, without 

 claw, equal to or longer than the commissure, the rictal bristles obso- 

 lete, wing-tip shorter than exposed culmen, ninth primary shorter than 

 sixth, the under parts at least partly yellow, upper parts olive-green, 

 and the fore-head and sides of head, in part at least, l)lack in adult 

 males. 



Bill decidedh' (usually much) shorter than head, narrowly conoidal, 

 gradually tapering to the tip, the maxillary tomium with subterminal 

 notch present but indistinct; culmen straight, or nearly so, to near tip, 

 where very slightly decurved. Nostril small, in lower anterior portion 

 of nasal fosstv, longitudinally oval or subcuneate, overhung by a rather 

 broad meml)ranous operculum. Rictal ))ristles ol)solete. Wing rather 

 short, much rounded (seventh to fifth primaries longest, ninth shorter 

 than sixth, sometimes shorter than tirst); wing-tip shorter than exposed 

 culmen. Tail variable in relative length, never conspicuously shorter 

 than wing, usually nearly the same length, rarely (in (r. fwl-soni only) 

 decidedl}' longer; much rounded (sometimes almost graduated), the 

 rectrices subacuminate at tips. Tarsus decidedly more than one-third 

 as long as wing, its scutella distinct; middle toe with claw shorter 

 than tarsus; l>asal phalanx of middle toe united for most of its length 

 to outer toe, separated for most of its length from inner toe. 



Colo ration. — Above olive-greenish, beneath at least partly, some- 

 times wholl}^, yellow; adult males with forehead and at least part of 

 sides of head black. 



Nidification . — Ter res tr ia 1 . 



Range. — The whole of temperate North America and continental 

 tropical x\merica; Bahamas, and (in winter) Cuba, Porto Rico, Haiti, 

 and Jamaica. 



In only one species, G. nelsoni, is the tail much longer than the wing; 

 in all the others it is either shorter (often decidedly so) or of about equal 

 length. G. semlflava, G. speclosa., and G. nehoni have the outermost 

 (ninth) primary shorter, or at least not longer than the first; in all the 

 others it is longer, usually longer than the third. The adult males of 

 all the North and Middle American forms, as well as the South Amer- 

 ican (Ecuadorean) form of G. semiflava, have the malar region black, 

 thus forming part of the black "mask;" in the two exclusively South 

 American species ( G. velata and G. (equinoctial Is) the malar region is 

 yellow, like the under parts; they further differ from all the others in 



''Tett, Erde; bXvnis, nom. prop." 



