( 16 ) 



M. satxrtdiius areiioceuK Chajim.* from Bahia, difi'ers from .1/. s. Jratir liy 

 paler coloration and by its much longer, stronger hill. The leni^th of the bill 

 varies, in seven adnlt birds, from 23 — 26 mm. 



3. Thryophilus albipectus rufiventris (Scl.). 



[ Tliri/oHitiiii.i albipei-liia Cabanis. in Schomburgk, Reixen Brit, (jniniia iii. 673 (1848. — Cayenne).] 

 Thrijothiiiua rufirintrix Sclater. P. X. .S. Loml. 1870. p. .32S (Goia?, and Mattogrosso). 

 Thryothorus ijiilhniithi (nee Lawrence) Pelzeln, Zur Ornilh. Bia^. i. lH('i7. p. 47 (Cuyabii, Goiaz) ; 

 Allen, Bull. Aniei: Mu«. iii. 1891. p. 343 (Chapada). 



No. 2125. ? ad., Rio Thesonras, May HMKi.— Wing 04; tail 40 ; bill 20 mm. 



Nos. 1833, 1834, 1944, 1951. c?c? ad., cjt? jiiv., Goyaz, March.— Adults : 

 Wing 66; tail (damaged); bill 10. Young: Wing <i.-,, (31; tail 50, 40; bill 

 19 mm. 



Nos. 2200, 2249, 2378, 2407. c?c? ad., Rio Araguaya, June and August.— 

 -VVing 68—711; tail 51—53; bill 19—20 mm. 



Nos. 2203, 2313, 2400. ? ? ad., Rio Arnguaya, June and July.— Wing 63, liS ; 

 tail 50 ; bill 10 mm. 



In the above specimens the whole lower surfixee (e.xcept the white throat) 

 is unifonii ochraceons-buff, rather deeper ochraceous on the flanks and under 

 tiiil-coverts, and somewhat paler, about bright bnff (Ridgw. v. 13) on the foreneck. 

 There is never any trace of brownish on the flanks, this colour being always more or 

 less pronounced in the Upper Amazoniau form as well as in 7'. a. albipecttas (Cab.). 

 Adnlt birds show distinct blackish longitudinal streaks on the ear-coverts, which 

 almost are uniform white in the two young ones (Nos. 1833, 1844). 



T. a. r II fi cent lis differs from the form inhabiting the Upper Amazonian district 

 (cf. Xor. Zool. xiv. 1907, p. 3, form e) in its greater dimensions, especially longer tail, 

 decidedly longer and stronger bill, purer ochraceous nnder-parts without any 

 brownish snff'nsion on the flanks, and by its somewhat paler upper surface ; 

 from T. a. albipectus it may be distinguished by its longer bill, more uniform 

 nuder-parts, etc., and from 7'. a. i/alhraitlii (Lawr.), of Panama and Santa 

 Marta, by its much longer tail and conspicuously streaked ear-coverts. 



In W'estern Mattogrosso and Eastern Bolivia T. a. rujicentris is replaced by 

 T. a. M/'iicn- (Pelz.), which differs only by its much smaller size and shorter, 

 weaker l)ill. In coloration the two forms are absolutely alike. 



Their distribution is as follows : 



(a) r. uVAjiectus rufreiitris (Scl.). Eastern Mattogrosso : (Juyaba (Natterer), 

 Chapada (Smith). N.E. San Panlo : Barretos on the Rio Grande (Garbe— ? ad. in 

 Mns. Paulista, examined by me). Goyaz : city of Goyaz (Baer, Natterer), Rio 

 Thesouras, Rio Araguaya (Baer), Rio Panmahyba (Behu— J ad. in Mus. H. v. 

 Berlepsch e.xamiued), Leopoldina, Araguaya (von den Steinen— J ud. i.i Berlin 

 Museum examined). 



\\ SS ad. : Wing 0(1-70; tail 51—53; bill 10—20 mm. 



6??ad. : „ 64-6S ; „ 40—51; „ 19-20 mm. 



(i) T. albipectus iniiior (Pelz.). 

 Thryufhunis minor Pelzeln, Zur Ornith. Bran. i. pp. 47, 66 (1867.— Villa Bella de Mattogrosso and 



Rio Guaporu). 

 Tliryopliilus rufiventris (nee Sclater) Salvadori, Bvll. J/««. Turiiio x. No. 208, 1895. p. 3 (Corumb;t 



Mattogrosso) ; idem. I.e. xv. No. 378, 1000. p. 3 (Urucum, Mattogrosso). 



• MiiiiKS arcnaeeiis Chapman, Aiil\ ISUO, p. 135. 



