62 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



Range. — Isthmus of Panam^ to Cayenne and Amazon Valley. 

 (At least four species.)" 



KEY TO THB SPECIES OP MYRMOTHERULA. 



a. Under parts white, streaked with black. (Panamd to Guiana and western Ecuador.) 



Myrmotherula surinamensis, adult male (p. 62). 

 aa. Under parts neither white nor streaked with black. 

 h. Under parts buffy, deepening into tawny on chest . 



Myrmotherula surinamensis, adult female (p. 62). 

 hh. Under parts of body pale straw or primrose yellow. 

 c. Pileum narrowly streaked with pale yellow or yellowish white; throat white. 

 (Panama to Cayenne and Peru). Myrmotherula pygmaea, adult male (p. 64). 

 cc. Pileum streaked with pale rufous or tawny; throat buff or pale ta^vny. 



Myrmotherula pygmsea, adult female (p. 64), 



MYRMOTHERULA SURINAMENSIS (Gmelin). 



SURINAM ANTWREN. 



Adult male. — Pileum, liindneck, back, and scapulars black, nar- 

 rowly streaked with white, the feathers of back extensively wliite 

 basally; rump plain gray (nearly no. 6), much paler posteriorly; 

 upper tail-coverts dusky, indistinctly margined terminall}^ with 

 whitish; tail black, the rectrices tipped with white and edged on 

 middle portion \\dth the same; wings black, the middle and greater 

 coverts broadly tipped with white (formmg two very conspicuous 

 bands across wing), the remiges edged (except on basal portion of 

 distal secondaries and proximal primaries) wdth white; under parts 

 wliite, the throat narrowly, the chest, breast, sides, and flanks 

 broadly, streaked with black; under wing-coverts and broad edgings 

 to inner webs of primaries white; maxilla dull black, mandible dull 

 wliitish (in dried skins) ; legs and feet pale yellowish gray (in dried 

 skins); length (skins), 90-107 (96); wing, 49.5-52.5 (51); tail, 

 26-28.5 (26.9); culmen, 14-15.5 (15); tarsus, 16.5-18.5 (17.2); 

 middle toe, 9.5-10.5 (9.9).'' 



Adult female. — Pileum bright tawny, the occii)ut and posterior 

 part of crown streaked with black, the hindneck more buffy and with 

 black streaks broader; back and scapulars black, streaked with 



« The following species, referred to Myrmotherula by Dr. Sclater, I have not seen 

 and therefore have no very clear idea of the limits of the group: M. guttata (Vieillot), 

 M. spodionota Sclater and Salvin, M. atrogularis Taczanowski, M. Juvmatonota (Sclater) 

 M. pyrrJionota Sclater and Salvin, M. erytlirura Sclater, M. erythronota (Hartlaub), 

 M. hauxveUi (Sclater), M. longipennis Pelzeln, M. brevicauda (Swainson), M. 

 urosticta (Sclater), M. inornata Salvin, M. unicolor (M^ndtries), M. longicauda Ber- 

 lepsch and Stolzmann, M. sororia Berlepsch and Stolzmann, M. guayahainhse Sharpe, 

 M. lafresnayeana (D'Orbigny), M. viduata Hartert, M. sanctxmartiv Allen, M. behni 

 Berlepsch and Leverkuhn, and M. boliviana Berlepsch. It is not unlikely that 

 when all these species can be critically compared a further subdivision of the genus 

 may be required. 



& Four specimens. 



