BIRDS OF ARGENTINA, PARAGUAY, URUGUAY, AND CHILE 119 



aggressive and fought savagely, often pursuing some vanquished 

 competitor for some distance. A young bird two v^'eeks old, seen 

 on December 3, may have belonged to this species. 



On January 31, 1921, on the Laguna Castillos, below San Vicente, 

 Uruguay, F. armillata was found in bands that rested on the low 

 shores and swam out into the lake as I came near. A number had 

 been affected by alkali in the water so that I picked up a male in 

 condition to skin and secured skulls from two more that lay dead 

 on the shore. 



At Concon, Chile, on April 24, I examined one that had been 

 killled by a hunter. 



An adult female shot on October 29 had the soft parts colored 

 as follows : Bill in general slightly brighter than olive yellow ; space 

 on culmen from above nostril to center of frontal shield, and spot 

 on base of bill immediately behind nostril burnt lake, shading on 

 outer margin to Brazil red; iris Vandyke red, slightly clouded with 

 duller markings; tarsus and toes in general olive lake; marginal 

 webs and borders of scutes washed with deep neutral gray ; spot on 

 rear of crus dull English red ; claws dull black. 



The feet in the present species are enormous, much larger than 

 in other species with which it is associated, and have proportionately 

 broader lobes. The bird, in addition, is heavy in body and appears 

 large when seen at a distance. In life adults of the three coots 

 of this region may be distinguished without difficulty by the color 

 of the frontal shield and bill. In armillata a dark-red mark on the 

 lower margin of the shield and base of the bill crosses the other- 

 wise light color of these parts. In leucoftera bill and shield are 

 entirely light, while in i^ffrons the shield is dark red. According 

 to Doctor Dabbene,* F. armillata in swimming does not hold the 

 tail erect over the back, as is customary in ru-fifrons^ but drops it 

 in the manner of a tinamou. 



Though the three are separated without trouble in the field, or 

 when freshly killed, there is often difficulty in naming dried skins. 

 The following notes may be of assistance in separating them : 



flw* Frontal plate produced posteriorly in a narrow acute point ; tail longer 

 (58 to 62 mm.) ; frontal plate dark red; outer web of tenth primary 

 usually plain (occasionally with a faint white margin) Fulica rufifrons. 



(/.' Frontal shield rounded or if pointed posteriorly not greatly elongated ; tail 

 shorter (47 to 56.5 mm.) ; frontal plate orange or yellow; outer web of 

 first primary bordered with white. 



?>.* Feet relatively larger ; crus more or less reddish ; secondaries plain or very 

 slightly margined with white at extreme tip Fulica armillata. 



6.^ Feet relatively smaller ; crus greenish or yellowish ; secondaries tipped 

 prominently with white Fulica leucoptera. 



«An. Mus. Nac. Hist. Nat. Buenos Aires, vol. 28, July 19, 1916, p. 190. 



