50 NORTH AMERICAN BIRDS. 
Orpver TUBINARES.—Tue Tuse-nosep Swim- 
MERS,. (Page 1.) 
Families. 
a', Wings very long; nostrils opening in anterior end of horizontal nasal tubes. 
bt. Nasal tubes widely separated by the intervening culmen; size very large 
(equal to a large goose or larger); wing very narrow, with very nu- 
Merous (39-50) reMiGes........seeeeereeeeeeereee Diomedeidz. (Page 50.) 
b%, Nasal tubes united, and resting upon the basal portion of the culmen; size 
and other characters extremely variable, but usually medium-sized or 
small, and remiges never more than 39 (usually 30, or less). 
Procellariidz. (Page 53.) 
a?, Wings very short, and general appearance decidedly Auk-like; nostrils opening 
upwards, as parallel longitudinal slits, at very base of culmen. 
Halodromide, (Extralimital.) 
Famity DIOMEDEIDA®.—Tue ALBaTRossEs. (Page 50.) 
Nest a mound-like heap of grasses, etc., with depressed top, built upon the 
ground in open situations, on oceanic islands. Egg single, ovate, or elliptical ovate, 
white, sometimes speckled or sprinkled on larger end with reddish brown. 
Genera. 
a’. Sides of lower mandible without longitudinal groove; wing three or more times 
as long as the short, rounded tail. 
b. Upper division of the bill much broadest at base, where joined closely to the 
leteral CivisiOn :ccssssisdssstussemesvveiessseseasacseeessens Diomedea. (Page 50.) 
bo. Upper division of the bill narrow, and of equal width from the middle of 
the culmen to the base, where widely separated from the lateral division 
by the interposition of a strip of naked skin extending from the nasal 
tubes to the forehead...............cceecseeeees Thalassogeron. (Page 52.) 
a’. Sides of lower mandible with a distinct longitudinal groove, extending the entire 
length of the lateral division; wing only about twice as long as the gradu- 
ated or wedge-shaped tail...........ccccccssecssseeceeseees Pheebetria. (Page 53.) 
Genus DIOMEDEA Linwaus. (Page 50, pl. XIII, figs. 1, 2.) 
Species. 
a’. Culmen very concave; feathers at base of upper mandible extending in an angle 
nearly or quite to the base of the nasal tube, those at the base of the lower 
mandible forming a still more decided angle. (Subgenus Diomedea.) 
