294 BULLETIN 133, UNITED STATES NATIONAL MUSEUM 



marked degree the characters of large size and dark coloration that 

 distinguish the southern form. 



XENOPSARIS ALBINUCHA (Burmeister) 



Pachyrhamphus albinucha BuRMEasTER, Proc. Zool. Soc. London, 1868, p. 

 635. (Rio de la Plata, near Buenos Aires.) 



Near Laguna Wall, 200 kilometers west of Puerto Pinasco, an 

 adult male was taken September 25, 1920, as it watched alertly for 

 insects from a low perch at the border of a thicket of vinal. The 

 bill in this specimen is decidedly larger than in a topotype of the 

 species examined in the collections of the United States National 

 Museum, and may perhaps represent a distinct form. The culmen 

 from the base measures 12.3 mm., while in the bird from Argentina it 

 is 10.4 mm. Difference between the two in heaviness of bill is no- 

 ticeable. A second specimen from Monteagudo, Tucuman, a male, 

 in the collection of the Museum of Comparative Zoology, agrees in 

 size with the bird from Buenos Aires (culmen from base 11 mm.). 



CASIORNIS RUFA (Vieillot) 



Thamnophilus rufus Vieillot, Nouv. Diet. Hist. Nat., vol. 3, 1816, p. 316. 

 (Paraguay.) 



Near Las Palmas, Chaco, a female of this cotinga was shot July 

 13, 1920, and another, placed in alcohol, was taken July 21. Males 

 were secured at Kilometer 80, west of Puerto Pinasco, Paraguay, 

 September 11 and 16, and others were seen at Kilometer 25, Septem- 

 ber 1, and on the eastern bank of the Rio Paraguay, opposite Puerto 

 Pinasco, on September 30. The female from Las Palmas is deeper 

 rufous above than others examined. A specimen shot July 21 had 

 the tip of the bill dull black; base of mandible tilleul buff; base of 

 maxilla avellaneous ; iris natal brown ; tarsus and toes deep purplish 

 gray. Hellmayr '^^ considers C. fusca Sclater and Salvin, of which 

 I have seen only one skin, a race of rufa Vieillot. 



A retiring species, the present form was found singly or in pairs 

 only in dense undergrowth in heavy woods, where it hopped about 

 from perch to perch or remained motionless among green leaves in 

 the pose of a flycatcher. The call note, heard rarely, resembled 

 tsa ah given in a high-pitched tone. 



HABRURA PECTORALIS PECTORALIS (Vieillot) 



Sylvia pectoralis Vieillot, Nouv. Diet. Hist. Nat., vol. 11, 1817, p. 210. 

 (Paraguay.) 



An adult male secured at Las Palmas, Chaco, on July 17, 1920. 

 agrees in size and color with another taken (with an adult female) 



«8Nov. Zool., vol. 15, June, 1908, p. 56. 



