( 337 ) 



Nos. 743, 793, 538. ¥ ?, Calama, 1. xi. 1907 ; AUianca, 19. xi. 19u7 ; Jamary- 

 ginho, 12. ix. 1907.— Wing 87—92 ; tail 71—74 ; bill 24—2.5 mm. 



" Iris red, feet plumbeous, bill black." 



The males have rather more white in the tail than a series from Borba and 

 Hnmaytha, the two (in No. 395 the three) outer rectrices of each side showing a 

 distinct white apical margin and several white spots or bands on their inner web. 

 They form the transition to T. m. semifasciatus (Cab.), in which, however, the 

 white marliings are more numerous (about eight to ten on each featlier) and much 

 more regular. A specimen from Itaitiiba, left bank of the Tapajoz (cf Nov. Zool. 

 xiv. p. 16), is intermediate between semifasciatus (from Parii, Guiana, etc.) and the 

 examples from the Rio Machados. 



T. m. barbae inhabits both banks of the Rio Madeira, but is not known to 

 occur elsewhere. 



[201. Thamnophilus nigrocinereus tschudii Pelz. 



Thamnophilus tscliiitlii Pelzaln, Ziir Oni. Bras. ii. p. 141 (1868. — Borba, Rio Madeira). 



Right bank : Borba (Natterer). Not obtained by Mr. Hoffmanns. 



Occurs also on the Peruvian Amazons (Ljuitos, Nauta), whence I have seen 

 specimens in the British Museum and in Count Berlepsch's collection. 



T. nigrocinereuSj T. cinereoniger, T. huberi, and T. tschudii are mere 

 geographical representatives of the same type, hence more properly designated by 

 trinomials. The last-named form is slightly more dift'ereutiated than the three 

 others, yet gnfiScient evidence of intergradation is furnished by a series of adult 

 males as shown below. In the following lines a condensed review of the dis- 

 tinguishing characters, together with the principal synonymy and a short account 

 of the range of the four races, is given, which, it is hoped, may aid naturalists in the 

 determination of these scarce birds. 



(a) 7. nigrocinereus nigrocinereus Scl. 



Thamnopliilus nigruciiiereun SclsiteT, Proc. Zool. Sue. Lund, xxiii. 1855. p. 19. pi. Ixxxi (1855. — 

 Pari) ; Sclatcr & Salvin, P. Z. S. 1867. p. 575 (Rio Tocaotins, Mexiana) ; Sclater, Cat. BinU 

 Brit. Mas. xv. p. 194 (Lower Amizons) ; Hagcaann, Znolug. Jahrh., .ibt. Syst., etr. xxvi. 1907. 

 p. 33 (Mexiana) ; Snethlage, Juurti. f. Urn. 1907. p- 283 (Mexiana, Marajd, Para). 



T. cinereuniger (errore ' nee Pelz.) Saethlage, Joiirn. f. Orn. 1907. p. 283 (Marajo, Monte 

 Alegre). 



Hab. N.E. Brazil : Para (Snethlage, etc.), Rio Tocantins (Wallace), Mexiana 

 (Wallace, Hagmann), Marajo (Snethlage), Monte Alegre (Snethlage). 



<S ad. Pileuni, mantle, sides of head, throat, and foreneck sooty black, the 

 pilenm somewhat glossy ; feathers of upper back largely white at base, some of 

 them with slaty margins ; lower back and rump slate-grey, abruptly contrasted 

 with black of mantle ; U])per tail-coverts black with narrow white apical edges ; 

 upper wing-coverts black, each feather with a distinct white apical margin. 

 Remiges and rectrices black, narrowly edged with white, the former exteriorly, the 

 latter at the tip. Breast, abdomen, and under tail-coverts clear slate-grey. 



Wing 78—82 ; tail 58—02 mm. 



? ad. Pileum dull sooty blackish, most of the feathers indistinctly edged with 

 slate-grey; back pale rufescent olive-brown; feathers of upper back extensively 

 white at base ; wing-coverts dusky with cinnamon-brown mai'gins ; remiges 

 and rectrices dusky, slightly edged with rufescent brown, the outer tail-feathers 



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