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223. Myrmotherula assimilis Pelz. 
Myrmotherula assimilis Pelzeln, Zur Orn. Bras. ii. pp. 81, 152 (1868,—Borba, Rio Madeira ; 
below Poiares, Rio Negro ; Rio Amajaii); Hellmayr, Nov. Zool. xiv. p, 384 (Humaytha). 
Nos. 28, 415. dad, d imm., Calama, 12. vi., 17. viii. 1907—Wing 53, 54; 
tail 29, 304; bill 134, 14 mm. 
No. 874. ¢ imm., Marmellos, 27. xii. 1907.—Wing 58; tail 29; bill 14 mm. 
Nos. 824, 870. dd juv., Marmellos, 18, 26, xii. 1907.—Wing 51, 54; tail 
30, 31; bill 14 mm. 
The series fully confirms the distinctness of MJ assimilis. The young males 
have the lower parts dingy (greyish) white, slightly shaded with buffy here and 
there, some of the upper wing-coverts brown edged with buff, etc., all remains of 
the juvenile plumage. For characters and range ef. /.c, p. 384. 
224. Ramphocaenus melanurus amazonum Hellm. 
[Ramphocaenus melanurus Vieillot, Nouv. Dict. xxix. p. 6 (1819,—*“ Brésil, par Delalande fils,” se. 
Rio de Janeiro).] 
R. m. amazonum Hellmayr, Nov. Zool. xiv. p. 66 (1907.—Teffé, Rio Soliméens) ; idem, Zc. p. 373 
(Humaytha, Borba). 
Nos, 48, 383. d ad., d imm., Calama, 15. vi., 12. viii. 1907—Wing 53, 54; 
tail 50, 473 ; bill 22—23} mm. “ Iris brown, feet plambeous, bill grey.” 
Nos. 14, 182. ¢¢ ad., Calama, 10. vi., 7. vii. 1907.—Wing 48, 53; tail 46; 
bill 22 mm. “ Iris brown, feet and bill grey,” 
The series fully corroborates the characters of the subspecies. The Calama 
birds differ from R. m. albiventris (represented in the Munich Museum by specimens 
from Saint-Laurent-du-Maroni, French Guiana, Le Moult coll.) by the much paler 
“creamy buff” sides of the neck, by lacking the rafous tinge on the nape, and by 
having the chest and sides of breast faintly washed with creamy. The outer 
rectrices are tipped with smoky grey. 
R. m. amazonum ranges from the Rio Madeira westward to Eastern Peru 
(Yurimaguas, Santa Cruz, Chyavetas) and northward to the Rio Solimoéns (Teffé). 
Farther to the south, on the Guaporé, one of the headwaters of the Rio Madeira, 
it is replaced by R. melanurus sticturus Hellm., of which Natterer obtained a good 
series at Villa Bella de Mattogrosso, Engenho do Gama, and S&o Vicente. Cf. 
Nov. Zool. xiv. 1907. pp. 373-5, where a short review of the geographical races 
of R. melanurus is given. 
[225. Sclateria argentata (Des Murs). 
Cf. Nov. Zool. xiv. 1907, p. 375 (Humaytha). 
Heterocnemis albiventris Pelzeln, i.c. p. 161 (Guajaraguacu, Girao, Borba), 
Both banks of the Rio Madeira: Guajaraguacu, Salto do: Girao, Borba 
(Natterer), Humaytha (Hoffmanns). Also found on the Peruvian Amazons, Rio 
Negro, and Orinoco,*] 
[226. Sclateria schistacea leucostigma (Pelz.).t 
Cf. Hellmayr, Nov. Zool. xiv. 1907. p. 376 (Borba). 
Right bank of the Rio Madeira : Borba (Hoffmanns). } 
* In the Cat. Birds Brit. Mus. xv. p. 277, a specimen from Bartica Grove (Whitely) is recorded s.n. 
H. argentata, I have examined the bird; it is without doubt a young male of Selateria schistacea 
leucostigma (Pelz.). . 
} I have examined the bird from the Rio Jurué, 
recorded by Ihering s.n, Sclateria leucostigma (Rev. 
Mus. Paul. vi. p. 442). It turns out to be a male of 
Myrmelastes hyperythrus (Gould), 
