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INTRODUCTION. 
Family STERNID.®. Terns. 
Genus STERNA, Linn. Cosmopolite. 
(ten. char. Bill more or less long, strong, with the culmen slightly curved to the tip, which is acute ; the 
gonys straight, and half the length of the bill ; the nostrils lateral, placed towards the middle of the bill, and longi- 
tudinal, with the frontal plumes advancing close to, or near, the opening. Wings very long and pointed, with the 
first quill the longest. Tail more or less long and generally forked. Tarsi more or less long and slender. Toes 
moderate, the two outer ones nearly equal, and the three anterior ones united by an indented web; the hind toe 
very short; the claws moderate, slightly curved, and acute. 
Genus HYDROCIIELIDON, Loie. Southern Hemisphere. 
Gen. char .—Bill strong, short, with the culmen rather arched to the tip, which is acute ; the sides compressed, 
and the gonys long, straight, and advancing upwards to the tip; the nostrils basal, lateral, and longitudinal, with the 
frontal plumes projecting to the opening. Wings long, with the first quill the longest. Tail moderate and slightly 
emarginated. Tarsi rather shorter than the middle toe and slender. Toes long, slender, the two outer toes equal 
and longest, the three anterior toes united only at the base, the web continuing along the inner margin of each toe ; 
the hind toe moderate and slender ; the claws also long and slender. 
Order G R A L L M. 
Family KALLIDiE. Rails. 
Genus RALLUS, Linn. Cosmopolite. 
Gen. char. Bill longer than the head, slender, and straight, with the culmen slightly curved from the front 
of the nostrils, and the sides compressed to the tip, which is obtuse and slightly emarginated ; the gonys long and 
slightly curved upwards ; the nostrils placed in a membranous groove, which extends for two thirds the length of the 
bill, with the opening exposed and linear. Wings short, with the second and third quills equal and longest. Tail 
short and rounded. Tarsi moderate, shorter than the middle toe, and covered with transverse scales. Toes lono- 
and rather slender, the inner toe shorter than the outer, both free at their base ; the hind toe short and slender* 
the claws short, compressed, and very acute. 
Genus ORTYGOMETRA, Linrums. Australia, New Zealand, and Polynesia. 
Gen. char. Bill shorter than the head, and more or less strong, with the culmen keeled, slightly curved, and 
the sides compressed to the tip, which is slightly emarginated; the gonys short and ascending; the nostrils lateral 
and placed in a membranous groove, with the opening exposed, linear, and near the middle. Wings moderate, 
with the second and third quills equal and longest. Tail short and graduated. Tarsi rather robust. Toes more 
or less long and slender, with the inner toe rather shorter than the outer, the hind toe very slender, and rather 
short ; the claws moderate, compressed, and acute. 
Genus OCYDROMLS, Wagler. Endemic. 
Gen. char. Bill rather long, and very strong, with the culmen slightly curved and the sides much compressed 
to the tip, which is slightly emarginated ; the gonys short and ascending ; the nostrils lateral, and placed in the 
