« 



I 



y ,. 



''^1 



m 



42 KEY TO FAMILIES. 



A. Tip of tlio upper mandible more or less swollen, rounded, and 

 sharply pointed; upper parts, including wings, and sometimes tho 

 entire plumage, dark sooty blackish, sometimes irregularly barred ; 

 tail always dark, the middle feathers longest. . . . Family Uterco- 

 rariidiK : Skuas and Jaeoeks (Fig. (J, a), p. 05. 



B. Upper mandible curved but not swollen at tlio end; tail generally 

 white, sometimes tipped with black ; the tail-feathers usually of about 

 equal length. . . . Subfamily Larina, : Gui.ls (Fig. 0, i), p. 67. 



Fio. 7. 



Fio. 8. 



C. Bill straight, not hooked and sharply pointed ; outer tail-feathers 

 generally longer than the middle ones. Subfamily Sternince. : Terns 

 (Fig. 7), p. 70. 



D. Bill thin and bladelike, the lower mandible much longer than the 

 upper one. . . . Family liynchopidoe : Skimmers (Fig. 8), p. 85. 



, Fio. 9, 



Order HI. Tubiaares.— Albatrosses, Petrels, and Fi'LMars. 



Bill hawklike, the tip of the upper mandible generally much enlarged ; 

 nostrils opening through tubes; hind toe reduced to a mere nail, and 

 sometimes entirely wanting. 



A. Size very large, nostrils separated and on either side of the bill. • . . 

 Family Diomedeidie : Albatrosses (Fig. 9, a), p. 80. 



B. Size smaller, nostrils joined and placed on top of the bill. . . . 

 Family ProcellariidcR x Petrels, Fulmars, and Shearwaters (Fig. 



9, 6), p. 80. 



