382 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, I50 



pared to palliatus these average darker above, have less white on 

 the inner webs of the inner primaries, and the white of upper 

 breast heavily mottled with black, a pattern that in some extends a 

 short distance down the sides. At the Isthmus of Tehuantepec this 

 mottled pattern tends to disappear. Few oystercatchers have been 

 recorded on the Pacific side of Guatemala, there are none known 

 for El Salvador, western Honduras, and Nicaragua, and only two 

 for western Costa Rica. The birds are found regularly only from 

 the Gulf of Panama south to southern Chile. In this region the 

 population has a clear-cut line between light and dark in the breast 

 pattern like palliatus, agrees with frasari in restricted white on the 

 inner primaries, but is darker, grayer on the dorsal surface. This 

 may be known as Haematopus palliatus pitanay, described from Peru, 

 with a range extended here to include Panama. 



On the Galapagos Islands the birds are much darker than any 

 others in the white-breasted group and have mottled upper breasts, 

 an extensive black pattern on the under wing coverts, and decidedly 

 larger feet. These are Haematopus p. galapagensis Ridgway, a 

 population definitely distinct from any others. 



Family CHARADRIIDAE : Plovers ; Chorlitos 



Plovers are birds of worldwide distribution in ice- free areas, 

 related to the sandpipers, snipes, and curlews, but with shorter and 

 somewhat more swollen bills. While several visit Panama in their 

 migrations only one, the collared plover or chorlito de collar, is a 

 resident on the isthmus. Most of the species range the sand beaches 

 of the seashore, but the golden plover in its passage flights comes 

 to open pastures and savannas. 



KEY TO SPECIES OF THE CHARADRIIDAE 



1. A long, slender crest ; throat black. 



Southern lapwing, Belonopterus chtlensis, p. 383 

 Head not crested ; throat white 2 



2. A very small hind toe ; axillars dark gray to black. 



Black-bellied plover, Squatarola squatarola, p. 384 

 No hind toe ; axillars pale gray or white 3 



3. Dorsal surface spotted and barred with white and black, some with golden- 



yellow ; breast mottled with dark gray. 



Golden plover, Pluvialis dominica dominica, p. 385 



Dorsal surface plain, or feathers tipped lightly with pale buff or grayish 



white ; breast not mottled 4 



