236 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 93 



NYROCA COLLARIS (Donovan) : Ring-necked Duck 



Anas collaris Donovan, British Birds, vol. 6, 1809, pi. 147 (Lincolnshire, England, 

 from specimen found in Leadenhall Market, London). 



On March 5, 1939, about 300 were seen in the Rio Papaloapan in 

 crossing from Alvarado to Tlacotalpam. On April 15, as I came 

 into the latter place, about 25 were swimming in the river, and the 

 following day an equal number were observed in returning to Al- 

 varado. 



NYROCA AFFINIS (Eyton) : Lesser Scaup Duck 



Ful if/ 11 la afflnis Eyton, A monograph on the Anatidae, 1838, p. 157 (North 

 America ) . 

 On March 5, 1939, half a dozen were recorded among the abundant 

 ring-necked ducks where the Rio Chiquito enters the Papaloapan 

 between Alvarado and Tlacotalpam. On April 15 about 20 were 

 seen near Tlacotalpam, and the following day nearly 200 were seen 

 between that point and Alvarado. The change in abundance in 

 March and April between this species and the ring-necked duck was 

 interesting. 



Family CATHARTIDAE 



SARCORAMPHUS PAPA (Linnaeus) 



Vultur Papa Linnaeus, Systema naturae, ed. 10, vol. 1, 1758, p. 86 (Surinam). 

 At Tres Zapotes I heard frequently of el rey zope and April 2 

 was called to see this bird, a king vulture, resting in a small tree a 

 hundred yards in front of our camp. While seeming unafraid, it 

 appeared nervous and moved about until it was partly concealed by 

 a thin screen of leaves. It rested much of the time with the head 

 lowered and thrust a little forward. The colors of the head were 

 brilliant, the red seeming especially intense. A short distance away 

 a large group of black vultures rested about some carcass that ap- 

 parently had attracted the king vulture. Near sundown the bird 

 flew away rather heavily with a loud swishing of its wings, flapping 

 them quickly for several beats and then spreading them to sail for 

 a short distance, the motion being exactly that of a black vulture 

 under similar circumstances. On April 7 I recorded one soaring 

 over the clearings at the edge of the great forest at Arroyo Corredor. 



CORAGYPS ATRATUS (Meyer) : Black Vulture 



Vultur atratus F. A. A. Meyer, Zool. Annalen, vol. 1, 1794, p. 290 (St. Johns 

 River, Fla.). 



This scavenger species, common through the country, was abun- 

 dant about the village of Tres Zapotes. Although they came all 

 around our camp, few alighted in the clearing, as we permitted no 

 waste to be thrown out and there was nothing to attract them. They 



