HYPOTHETICAL LIST. 369 



[Chen caerulescens (Linnaeus). Blue Goose. [169.1] 



Originally in the Hypothetical List as a questionable species. Transferred 

 to the regular List in the second edition. See p. 41, antea.] 



* [Anas rubripes tristis Brewster. Common Black Duck. [133.]' 



Entered in the Hypothetical List in the third edition as questionably dif- 

 ferent from A. rubripes and now transferred to the regular List. See p. 44, 

 antea.] 



Mergellus 2 albellus (Linnaeus). Smew. [131.1] 



Mergus albellus Linnaeus, Syst. Nat., ed. 10, I, 1758, 129. (in Europa 

 = Island of Gina near Smyrna, Turkey.) 



Audubon's sight record of this Old World species and several other alleged 

 occurrences in America are regarded as unsatisfactory and the species is there- 

 fore transferred to the Hypothetical List. 



Sarcoramphus ^ papa (Linnaeus). King Vulture. 



Vultur Papa Linnaeus, Syst. Nat., ed. 10, I, 1758, 86. (Mexico?) 



The record of this tropical American species from Arizona (cf. Coues, Bull. 

 Nuttall Orn. Club, VI, No. 4, Oct., 1881, 248) is regarded as unsatisfactory. 

 It has not been definitely recorded north of Mexico. Oiiginally entered as 

 Gypagus papa. 



Cathartes burrovianus Cassin. Burrough's Vulture. 



Cathartes Burrovianus Cassin, Proc. Acad. Nat. Sci. Phila., II, No. 8, 

 [June 24, 1845], 212. 



The type specimen taken by Dr. M. Burrough near Vera Cruz, Mexico, is 

 now regarded as Cathartes aura aura (Linnaeus), but all alleged North Amer- 

 ican specimens prove to be C. a. septentrionalis Wied (cf. Nelson, Pioc. Biol. 

 Soc. Wash., No. 19, Apiil 18, 1905, 122). Dropped from the List in the thiid 

 edition.] 



1 Erroneously called "Red-legged Black Duck" in the Hypothetical List of 

 the third edition. While both forms of the Black Duck were included under 

 the name rubripes in the regular List of that edition, with the vernacular name 

 of Black Duck, if they are to be separated "Red-legged" belongs exclusively 

 to the northern form, true rubripes, while tristis is the "Common" or southern 

 Black Duck. 



2 Mergellus Selby, Catal. Gen. and Subgen. Types Birds, 1840, 47. Type, 

 by monotypy, Mergus albellus Linnaeus. 



^Sarcoramphus Dumeril, Zool. Analytique, 1806, 32. Type, by subs, 

 desig., Vultur papa Linnaeus (Vigors, 1825). 

 25 



