( 18 ) 



The males agree with one of Natterer's typical specimens from Salto do Girao, 

 Rio Madeira, the three onter rectriees being white for more than half of their 

 length. The females are uniform chestnut below ; the top of the head and nape 

 very dark smoky grey, the back dull black. 



The examples from Cosnipata, S. Pern, are mnch larger, especially the tail 

 being longer, and the female is of a darker chestnut on the underpays. Should 

 additional Bpecimens confirm these differences, they must be separated sub- 

 specifically. 



F. bicolor has not previously been recorded from the Lower Amazons. 



44. Cercomacra sclateri Hellm. 



Cfr. Nov. Zool. siii. p. 370. 



No. 440. 6 ad., Itaituba, 12. i. 06. " Iris brown, feet and bill black."— Wing 

 64 ; tail 65 ; bill 18 mm. 



Agrees with the <? ad. from Para, though the lower parts are a shade 

 darker, but much lighter and more bluish slate-colour than in the type of 

 C. sclateri. 



45. *Cercomacra nigrescens approximans Pelz. 



[/'. n nostola nigrescent Cabauis & Heine, Mus. Heinean. ii. (1859), p. 10, descr. orig. £ (Cayenne)]. 

 I i.i,i approximate Pelzeln, Zur Ornith. Brazil, ii. (18G8), p. 158 (Engenho do Gama, 



Mattogrosso). 



No. 439. 3 ad., Itaituba, 12. i. 06. " Iris brown, feet and bill black."— Wing 

 07 ; tail 02 ; bill 17 mm. 



No. 4S5. ? ad., Itaituba, ','4. i. 06. " Iris greyish brown." — Wing 08 ; tail 59 ; 

 bill 18 mm. 



Not before recorded from the Lower Amazons. 



They agree exactly with typical specimens from Mattogrosso, being very 

 different from our series of C. tijrannina of Para, especially the female, which has 

 the front and sides of the head as well as the under parts of a deep ferruginous red 

 (cfr. Menegaux and Hellmayr, Bull. Soc. Philomat. Paris, 1906, p. 41). The male 

 is of a much darker slate-grey colour on the lower surface, and the white margins 

 to the upper wing-coverts are narrower and more restricted. 



Through the kindness of Oberamtmaun Heine I was enabled to examine the 

 type of P. nigrescens, and found it to belong to a Cercomacra species of which 

 the Tring Museum had received large series from Cayenue and Surinam. Although 

 very closely allied to C. approximans, they appear to represent a distinct form. 

 The males are darker, more blackish slate-grey, and the wing-coverts usually 

 uniform black, though sometimes with slight white apical margins. The females 

 agree with C. approximans in the coloration of the head and under parts, but the back 

 is rather more slaty olive (not so brownish), and the tail more blackish. Moreover, 

 in ' '. nign set ns the bill is, as a rule, a little broader and longer. The range of the 

 two subspecies is thus as follows : — 



a. C. nigrescens nigrescens (Cab. & Heine). Cayenne and Surinam. 



b. ('. nigrescens approximans Pelz. East Ecuador : Mapoto, Machay (spec, in 



Mus. v. Berlepsch examined). North Pern ; Iluambo, Chirimoto (spec, 

 in Mus. Berlepsch examined), Gnayabamba (Baron coll. ; c? ? in Brit. Mus. 

 exam.), Pebas (Castelnau & Deville coll. — a large series in Paris Museum 



