72 PATAGONIAN EXPEDITIONS! ZOOLOGY. 



gined with greyish brown. In many adults this greyish brown margin is 

 almost absent, the secondaries being nearly or quite white. 



Lower parts : Chin and throat grey mouse color. Rest of lower parts 

 shining satiny white shaded on the sides and flanks with dark slate. 



"Iris crimson; bill dark brown; legs and feet pale slate." (H. Durn- 

 ford.) 



The adult female in breeding plumage is similar to the adult male, 

 except that the area of black on the occiput is not so extensive, nor are 

 the plumes of the ear-coverts as elongated. 



Adults in non-breeding plumage are much like those in nuptial dress, 

 except that they lack the straw colored feathers above described as well 

 as the filaments to the crown feathers. 



Immature birds are like the adults in non-breeding plumage except 

 that the occiput and back of neck are dull white with a brownish tinge. 



Geographical Range. - - Patagonia, the Straits of Magellan, the Falk- 

 land Islands, Chile and the Argentine Republic northward to Peru. 



The Princeton University Expeditions did not secure this species and 

 the above measurements and descriptions are based on examples of this 

 bird in the collections of the British Museum of Natural History, and on 

 two individuals in the Princeton University Museum, from Museo de La 

 Plata, cited in full below. 



Darwin in his Voyage of the Beagle writes: "My specimens were ob- 

 tained from Bahia Blanca (September), Northern Patagonia, and the 

 Falkland Islands. In the former place it lived in small flocks in the 

 salt-water channels, extending between the great marshes at the head 

 of the harbour. At the Falkland Islands I saw (March) very few in- 

 dividuals ; and these only in one small fresh-water lake. Tarsi of the 

 same color as the plumage of the back ; iris of a beautiful tint, between 

 'scarlet and carmine red'; pupil black. Mr. Gould remarks that, 

 'This beautiful species of Podiceps is equal in size, and has many of the 



