( 337 ) 
Nos. 743, 793, 538. ?¢, Calama, 1. xi. 1907; Allianca, 19. xi: 1907; Jamary- 
sinho, 12, ix. 1907.—Wing 87—92 ; tail 71—74; bill 24—25 mm. 
“ Tris red, feet plumbeous, bill black.” 
The males have rather more white in the tail than a series from Borba and 
Humaytha, 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 markings are more numerous (about eight to ten on each feather) and much 
more regular. A specimen from Itaitiba, left bank of the Tapajoz (cf. Nov. Zool. 
xiv. p. 16), is intermediate between semifasciatus (from Pard, Guiana, etc.) and the 
examples from the Rio Machados. : 
T. m. borbae inhabits both banks of the Rio Madeira, but is not known to 
occur elsewhere. 
(201. Thamnophilus nigrocinereus tschudii Pelz. 
Thamnophilus tschudit Pelzeln, Zur Orn. Bras. ii. p. 141 (1868,—Borba, Rio Madeira). 
Right bank: Borba (Natterer). Not obtained by Mr. Hoffmanns. , 
Occurs also on the Peruvian Amazons (Iquitos, Nauta), whence I have seen 
specimens in the British Museum and in Count Berlepsch’s collection. 
T. nigrocinereus, T. cinereoniger, T. huberi, and T. tschudii are mere 
geographical representatives of the same type, bence more properly designated by 
trinomials. The last-named form is slightly more differentiated than the three 
others, yet sufficient 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) T. nigrocinereus nigrocinereus Scl. 
Thamnophilus nigrocinereus Sclater, Proc. Zool. Soc. Lond. xxiii. 1855. p. 19. pl. Ixxxi (1855.— 
Para) ; Sclater & Salvin, P. Z. S. 1867. p. 575 (Rio Tocantins, Mexiana) ; Sclater, Cat. Birds 
Brit, Mus. xv. p. 194 (Lower Amazons) ; Hagmann, Zoolog. Jahrb., Abt. Syst., etc. xxvi. 1907. 
p. 33 (Mexiana) ; Snethlage, Journ. f. Orn. 1907. p. 283 (Mexiana, Marajé, Pard). 
T. cinereoniger (errore! nec Pelz.) Snethlage, Journ. f. Orn. 1907. p. 283 (Marajé, Monte 
Alegre). 
Hab, N.E. Brazil: Pard (Snethlage, etc.), Rio Tocantins (Wallace), Mexiana 
(Wallace, Hagmann), Marajé (Snethlage), Monte Alegre (Snethlage). 
3 ad. Pileum, mantle, sides of head, throat, and foreneck sooty black, the 
pileam somewhat glossy ; feathers of upper back largely white at base, some of 
them with slaty margins; lower back and ramp slate-grey, abruptly contrasted 
with black of mantle ; upper 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—62 mm. ee j 
_ $ ad. Pileum dail 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 margins; remiges 
and rectrices dusky, slightly edged with rafescent brown, the outer — 
