Birds of the Hawaiian Group. 



Order LONGIPENNBS.— Long-winged Swimmers.' 



Families. 

 With the lower mandible not longer than the upper one and only moderately 

 compressed, while the covering of the upper mandible is made up of one solid piece 

 (/. r., with the seams fused together, no "nail" at the tip, etc.), through which the 

 nostrils are pierced. 



Family I/AR'IDi^. — Gulls and Terns. 

 Genera. 

 a. Bill rather short, and deeper at the angle than at the nasal openings ; the 

 upper mandible longer and bent down over the lower one; tail usually even (Sub- 

 family Larincs) ; tarsus not roughened nor serrate behind ; hind toe moderately well 

 developed ; culmen more than two-thirds the length of tarsus ; nostrils linear or linear 



ovate (Page 6. ) Larus. 



aa. Bill slender with both mandibles about equal in length ; tail slightly or de- 

 cidedly forked; angle of the lower mandible not prominent. (Sub-family Stertiince.') 

 b. Tail more or less deeply forked ; head without plumes at the gape ; tar- 

 sus shorter than the middle toe and claw; outer tail feathers the longest, and pointed; 

 tail generally more than half the length of the wing; bill compressed and slender; 

 tarsus never exceeding and generally shorter than the middle toe and claw ; depth of 



bill at base less than one-third the exposed culmen (Page 7-) Sterna. 



bb. Tail graduated, pointed; outer pair shorter than the next pair; middle 

 toe shorter than the exposed culmen ; distance from the angle of the gonys to the tip 

 of the bill less than to the gape. 



C. Tail feathers not all pure white. 



d. Fourth pair of tail feathers from the outside the longest; 



wing more than 9.50 (Page 9.) An'otis. 



dd. Third pair of tail feathers from the outside the longest; 



wing less than 9.50 (Page 9.) Microan'oiis. 



CC. Tail feathers all pure white (Page 9. ) Gygis. 



? For the Key to the Higher Orders see last pages of the Memoir, [261] (5) 



