INTKUDUCTION. xi 



VI. STEGANOPODES. Hind toi^ leiigtla-iu^d and incunilM-ed, and united to the inner 

 toe liy a comiilele web (small only in Tarh ijpdiihr) . Bill extremely variable, but 

 usually with a more or less extensible naked gular sac between the mandibular rami. 

 Nostrils obsolete. Habits altricial, yount; dasypredic in Tachypettdm, PhalacrocoracicUc, 

 Plotid(F, and PhmthontidcB, gynino])a;dic * in Pdccanidce and Sididie. Palate saurogna- 

 thous. Carotids double. 



VII. LONGrlPENNES. Hinil toe small or rudimentary, and elevated, sometimes almost 

 ubsuhte ; aiiteriur toes fully webbed. Bill more or le.ss compressed (nearly cylin- 

 drical only in some Stercorariidie), the nostrils linear, never tubular. Habits altri- 

 cial, young diisypcedic. Palate schizognathous. Carotids double. Eggs, two or more, 

 colored. 



VIII. TUBINARES. Hind toe absent or very rudimentary; anterior toes fully webbed. 

 Bill \'arialjle, but usually nearly cylindrical or compressed (rarely depressed), the ter- 

 minal portion strongly hooked. Nostrils tubular. Habits altricial, young dasypoedic. 

 Palate schizognathous. Carotids double. Eggs, never more than one, white. 



IX. PYGOPODES. Legs inserted far liackward, the tarsi extremely compressed. Anterior 

 toe.s fully webbed or else strongly lobed and with broad flat nails (Podicipidce). Bill 

 extremely variable. Habits prrecocial in Podidpi.dm and Colymbidce, altricial in Alcidce ; 

 young dasyptedic. Palate schizognathous. Carotids double, except in Podicipidoe and 

 some Alcida (e. </., genus Alle). 



The above arrangement is not strictly natural, but the division of Water Birds into " Waders " 

 and " Swimmers " is adopted for the convenience of the student. The Orders most nearly related 

 are the Herodiones and Steganopodes, Limicolce and Alcctorides, PhanicopUri and Anseres, and Longi- 

 penncs and Tuhinares. Of the Pygopodes (which as here defined is certainly not a properly 

 limited group) the Alckla: present many points of true relationship to the Tuhinares and Longi- 

 pcnnes, while the latter are not far removed from the Limicolce. The Podicipidm also appear to 

 resemble in some respects (perhaps only teleological) the Steganopodes. 



' Young birds are gymnopiedic when naked or very incompletely covered with down wlien hatched ; 

 c. g., tlie young of all Passeres, "Woodpeckeis, Pigeons, etc. 



