314 



STEKCORAEIIDj;. 



Family II. STERCORARIIDiE. 



Key to the Genera. 



a. Size larger, form robust; depth of the' 



hill at the exposed base nearly equal to 

 the leugth of the cere ; tarsus rather 

 shorter than the middle toe with its 

 claw; tail short, the central pair of 

 rectiices projecting about 0-5 inch . . . 



b. Size smaller, form more slender ; depth of 



the bill at the exposed base decidedly 

 less than the length of the cere ; tarsus 

 distinctly shorter than the middle toe 

 with its claw ; central pair of rectrices 

 projecting 3 inches or more in adults. . 



1. Megalestbis, p. 314. 



2. Stercorahius, p. 322. 



M. catarrhactes. 



antarctica. 

 catarrhactes. 



1. MEGALESTRIS. 



Catharacta*, Briinn. Orn. Bor. p. 32 (1764) M. catarrhactes. 



Lestris, Illiger, Prodr. p. 272 (1811 : part.). 



Cataractes*, Fleming, Phil. Zool. p. 263 (1822) 



Stercorarius, Vieill. N. Diet. (VHist. Nat. xxiii. 



p. 154 (1819) et auct. (partim). 



Catarracta *, Biy. Naum. 1854, p. 210 M. 



Megalestris, Bp. Cat. Parzudaki, p. 11 (1856) M. 



Buphagus, Corns, Pr. Philad. Acad. 1863, p. 125, ex 



Moehring (1752) M. catarrhactes. 



Bancje. North and South Atlantic, southern portion of the 

 Indian Ocean, Antarctic regions, and seas round New Zealand. 



Key to the Species. 



a. Bill longer in proportion to depth, terminal 



edge of cere markedly concave ; under surface 

 of body tawny or rich rufous ; back streaked 

 and mottled with rufous. 

 «'. Under surface tawny ; under wing-coverts 



blackish tinged with rufous catarrhactes, p. 315. 



b'. Under surface and under wing-coverts rich 



rufous ; back boldly spotted with chestnut . chilensis, p. 318. 



b. Bill shorter in proportion to depth ; terminal 



edge of cere less concave and more abrupt ; 

 under surface of body sooty brown to clay- 

 brown. 

 c'. Darker, upper and under surfaces sooty 



brown ; back little striated antarctica, p. 31 9. 



d'. Paler: head, neck, and under surface clay- 

 brown with a rich straw-yellow tint on the 

 upper neck maccormicki, p. 321. 



i 



* Previously applied to a subgenus of UriinK. 



