354 BULLETIN 133, UNITED STATES NATIONAL MUSEUM 



specifically related to it. A male, when fresh, had the bill, tarsus, 

 and toes black, the iris buffy olive. Known locally as thenca^ this 

 mocker was common through open scrub that covered large areas of 

 rolling hills. In general the bird is reminiscent of Mimus patagoni- 

 cus. It delights in resting quietly on the tops of low trees where it 

 has a commanding outlook, but at any danger may dive into safe 

 cover below. The black moustache and broad white superciliary 

 stripe are characteristic markings, while in flight the white tips of 

 the rectrices show plainly. Though the season was fall these 

 mockers sang more or less frequently, at intervals imitating other 

 birds, but giving many notes that appeared to be their own, that, 

 while distinctly mockerlike, differed from any that I had heard 

 previously. 



DONACOBIUS ATRICAPILLUS ATMCAPILLUS (Linnaeus) 



Turdus atricapiUus Linnaeus, Syst. Nat., ed. 12, vol. 1, 1766, p. 295. 

 (Brazil.) 



Two females, killed September 30, 1920, at Puerto Pinasco, Para- 

 guay, were preserved as skins, and a third bird, shot at the same time, 

 was placed in alcohol. 



Griscom^^ has recv5gnized a northern race of this bird as D. a. 

 hrachyptemis Madarasz, with a range from north central and north- 

 ern Colombia to eastern Panama, on the basis of lighter coloration 

 above. 



A female, when first killed, had the bill black, except for a spot 

 of pale Medici blue at base of gonys ; iris apricot 3^ellow ; tarsus and 

 toes fuscous ; bare skin on side of neck light cadmium. 



While passing in a narrow dugout canoe through the masses of 

 floating water hyacinth and grass, called camalote, that covered great 

 areas in the less rapid stretches of the Rio Paraguay, a bird showing 

 considerable white in the tail, dark above and buff below, flew up, 

 with a curious scolding note, to a perch on a grass stem. I shot it at 

 long range and after pushing in to it, with some trouble, was as- 

 tonished to find a Donacobius, a species that I had associated men- 

 tally with the brushy haunts of thrashers and catbirds. At once I 

 told ray Indian — who knew the bird as guira pecobd (pecoba being 

 banana) and said that they were found in banana plantations — that 

 we must secure others. After some search another popped out to 

 rest with hanging tail on a low perch, and as I shot this one half 

 a dozen more came into sight around us, flying for short distances 

 with tilting flight or perching near by with twitching wings and tail. 

 The plant growth in which they were found was luxuriant and 

 extensive, and the birds lived with all the seclusion of marsh wrens. 



45 Auk, 1923, pp. 215-217. 



