446 Supplement to the A. O. U. Check-List. aie 
earliest tenable designation (Committee American Ornithologists’ 
Union, Check-List North Amer. Birds, 1886, p. 73) the type of Colym- 
bus Linnaeus is determined as Colymbus cristatus Linnaeus, and con- 
sequently this generic name must be continued in use for the grebes. 
(Cf. Hartert, Brit. Birds, IX, 1915, p. 55.) 
Lunda Pallas versus Ahea !lege Alca| Boddaert. (Cf. Mathews, Austral- 
Avian Record, III, No. 2, Nov. 19, 1915, p. 37.) Change not ac- 
cepted, because Alca is to be regarded as clearly a typographical 
error for Alca. 
Pagophila alba (Gunnerus) versus Pagophila eburnea (Phipps). 
(Cf. Committee British Ornithologists’ Union, List Brit. Birds. ed. 2, 
1915, p. 394.) Change rejected, because the original description of 
Larus albus Gunnerus, in Leem’s Beskr. Finm. Lapp, 1767, p. 285, 
is considered recognizably applicable to the Ivory Gull. (Cf. Ober- 
holser, Proc. Biol. Soc. Wash., XXXII, Dec. 31, 1919, p. 199.) 
Larus hyperboreus Gunnerus versus Larus glaucus Briinnich. (Cf. 
Hartert, Hand-List British Birds, 1912, p. 202). Change rejected, 
because Larus glawcus Briinnich 1764 is rendered invalid by the 
prior Larus glaucus Pontoppidan 1763, which was applied to Larus 
canus Linnaeus. 
Sterna caspia Pallas versus Sterna tschegrava Lepechin. (Cf. Hart- 
ert, Hand-List British Birds, 1912, p. 192.) Change rejected, because, 
while Sterna tschegrava is sufficiently described, and has anteriority 
over Slerna caspia Pallas, Lepechin is clearly non-binomial in the 
article (Nov. Com. Acad. Sci. Imp. Petrop., XIV, pt. 1, 1770, p. 500) 
in which Sterna tschegrava is described. 
Daption Stephens versus Petrella Zimmermann. (Cf. Mathews, ‘The 
Auk,’ XXXI, No. 1, Jan., 1914, pp. 90-91.) Change rejected, be- 
cause Zimmermann is not binomial in the publication in question 
(Bartram, Reisen Nord- und Sud-Karolina, 1798, p. 293), nor is he 
a binary author accepted by the International Zoological Commission. 
Clangula Oken versus Bucephala Baird. (Cf. Hartert, British Birds, 
IX, No. 1, June 1, 1915, p. 7.) Change rejected because Bucephala 
Baird 1858 is preoccupied by Bucephalus Baer 1827, a genus of Ver- 
mes. Furthermore, the proper name for the genus is Glaucionetta 
Stejneger (cf. antea, p. 442). 
Clangula Oken versus Glaucion Kaup. (Cf. Committee British Orni- 
thologists’ Union, List Brit. Birds, 1915, p. 384.) Change rejected, 
because Glaucion Kaup 1829 is preoccupied by Glaucion Oken, 1816, 
a genus of Mollusca. 
Erismatura Bonaparte versus Oxyura Bonaparte. (Cf. Mathews, Novit. 
Zool., XVIII, No. 1, June 17, 1911, p. 9.) Change rejected, as Oxy- 
ura Bonaparte 1828 is considered preoc°upied by Oxyurus Swain- 
son 1827. 
Erismatura Bonaparte versus Cerconectes Wagler. (Cf. Mathews, 
Novit. Zool., XVIII, No. 1, June 17, 1911, p. 9.) Change rejected, 
