256 BULLETIN 133, UNITED STATES NATIONAL MUSEUM 



barely grown), were taken March 15, 19, and 21. In the identifica- 

 tion of these I have not had true fuliginiceps for comparison. Ac- 

 cording to Hellmayr^" the typical form differs from paranensis in 

 larger size (wing, 64 to 65 mm.) and in brighter brown on the dorsal 

 and ventral surfaces. The single male of paranensis secured has a 

 wing measurement of 56.8 mm. The three females measure, respec- 

 tively, 56, 56.5, and 57 mm. 



These birds were observed in little family parties that ranged 

 near the ground in the dense scrub that covered the hill slopes. 



It has been stated that the original specimens of this bird, secured 

 by Burmeister, came from Parana, a statement that must be incor- 

 rect, since paranensis is known only from the mountains of western 

 Argentina. In the United States National Museum are two skins, 

 secured from Burmeister, marked " Buenos Aires," while Burmeister 

 himself, in his Reise durch die La Plata-Staaten (1861, p. 469), 

 remarks under fuUginiceps, the name that he gave to this bird, "Bei 

 Parana." It must be supposed, however, that he took his specimens 

 during his travels in west Argentina. 



LEPTASTHENURA PLATENSIS Reichenbach 



Leptasthenura platensis Reichenbach, Handb. Spec. Ornith., 1851, p. 160. 

 (Rio de la Plata.) 



This bird was encountered only at Victorica, Pampa, from Decem- 

 ber 24 to 29, 1920, and Rio Negro, Uruguay, on February 18, 1921. 

 An immature male, taken at Victorica on December 29, and two 

 females of the same age on December 24 and 28, were preserved as 

 skins. A third immature female was secured at Rio Negro on the 

 date mentioned. L. platensis seems to constitute a distinct species, 

 as it differs constantly from L. aegithalo'ides, its nearest relative, in 

 the rufous instead of grayish tips on the outer rectrices and in the 

 more pointed crest. Immature examples of platensis are darker 

 above than adults and have shorter, more bushy crests ; though they 

 resemble L. a. pallida in color of the dorsal surface they may 

 be distinguished by the strongly rufescent tips on the outer tail 

 feathers. 



Leptasthenura platensis was noted in small flocks — family parties 

 of old and young — in trees of the densest foliage, such as the coro- 

 nillo and sombre todo {lodina rhoTnbifolia) ^ where they clambered 

 like titmice in a leisurely manner through the dense growths of 

 limbs. Their notes, a faint tsee-ee-ee, were weak, and it was diffi- 

 cult to follow them to their source, so that with their retiring habit 

 this species must often escape detection. When individuals were 

 located it was often a matter of several minutes before they could be 

 seen clearly. 



*» Nov. Zool.. vol. 28, September, 1921, p. 260 



