BIRDS OF WESTERN COLOMBIA. 1159 



identical with others from Costa Rica. T. n. atrimtcha replaces 

 T. 11. nceviibs on tlie western sides of the Andes, while the typical 

 f6rm is found in the Guianas, the Oiinoco Valley and its 

 tributaries. 



For the distinguishing charactei^s and geographical distribution 

 of the various laces of this group see my remarks in Abhandl. 

 Bayer. Akad. Wissensch. II. 01., vol. xxii. 3, 190G, p. 658 fT. 



117. Myrmotherula surinamensis pacifica, subsp. n. 



No. 2132. dad. Sipi : 30.ix.08.— Wing 53; tail 30; bill 

 16 mm. 



Nos. 1974, 2133. $ $ a,d. Guineo, R. Calima : G.viii.OB ; 

 Sipi : 30.ix.08.— Wing 52, 50 ; tail 30 ; bill 14|, 15 mm. 



[No. 09.788. d ad. Buenaventura, 23.iii.99.— Wing 52^ ; 

 tail 29; bill 15 mm. 



No. 09.787. 6 ad. Piano de los Monos, nearNaranjo, 2800 ft., 

 3.iv.99.— Wing 53 ; tail 3U ; bill 15 mm. 



No. 09,789-791. $ ? ad^ Buenaventura: 11, 18, 23.iii.99.— 

 Wing 51-52; tail 28-30; bill 14^-15 mm. 



These five specimens were collected by Eugene Andie.] 



" Iris dark brown, feet blue-grey, bill black, mandible grey." 



Adult. Differs from M. s. surinamensis Gm., in its longer 

 tail, much stronger as well as decidedly longer bill, wider white 

 tips to the outer rectrices (about 3 to 4 mm. on outermost pair), 

 and in having the upper back less variegated with black, while 

 the white interscapular blotch is much smaller in the male and 

 wholly absent in the female. The latter sex, too, has the top of 

 the head conspicuously clearer, about "tawny ochraceous" (Ridgw. 

 Nomencl. v. fig. 4) instead of " deep tawny " (I.e. v. fig. 1), and 

 the dark sti-ipes on the hind crown and nape are much duller and 

 less pronounced, being pale dusky olive instead of deep black. 



Type in the Zoological Museum, Munich : no. 09.789. $ ad. 

 Buenaventura, Choco, W. Colombia, March 11, 1899. E. Andr6 

 coll. 



Besides the above, I have examined in the Tring Museum 

 three males and three females obtained at Juntas, Rio Dagua, by 

 Messrs. Rosenberg and Raap, and in the British Museum 

 a single female from Remedios, collected by T. K. Salmon. 

 Dr. Hartert * has already alluded to this form, and, after studying 

 large series from various localities, I have no hesitation in 

 separating the Pacific birds from true M. s. surinamensis. 

 The typical race is confined to Surinam, French and British 

 Guiana, extending westwards to the Caura Valley, Eastern 

 Venezuela, while M. s. po^cifica ranges from Western Ectiador 

 through Colombia north to Veragua. The females of both forms 

 have the sides of the head, the foreneck and chest uniform 

 ochraceous, thereby differing very conspicuously from the 

 Amazonian race M. s. midtostriata Scl.f, 



* Nov. Zool. ix. 1902, p. 612. 



+ Cfr. Hellmayr, Nov. Zool. xvii. 1910, p. 345. 



78* 



