Older GAVIiE. 



Palate schizognathous. 



Nasals schizorhinal. 



Basipterygoid processes absent. 



Front toes entirely connected by webs. 



Wing aquiutocubital, i. e. the fifth secondary wanting. 



Bill simple, except in the subfamily Itliynchopince. 



CeiTical vertebrae fifteen. 



Coraco-humeral groove distinct. 



Furcula with hypocleidium. 



Primaries : ten large and visible, one minute and concealed. 



Aftershaft to the contour-feather present. 



Spinal feather-tract: well defined on the neck by lateral bare 

 tracts, and forked on the upper back. 



Bectrices twelve. 



Oil-gland tufted. 



Hypotarsus with two grooves. 



Young covered with down when hatched, and able to run in a 

 short time. 



Eggs seldom, if ever, exceeding three in number ; spotted or 

 scrolled with dark colours on a white, buff, or olivaceous ground. 



Synopsis of the Families. 



I. Bill without a cere ; sternum with two 



notches on each side of the posterior 

 margin ; toes partially or fully webbed ; 

 claws feeble or moderate Laridae, p. 3. 



II. Bill with a cere ; tip of the upper 



mandible hooked ; sternum with only 

 one notch on each side of the posterior 

 margin ; cseca much larger than in 

 Laridcf ; toes fully webbed, furnished 

 with large, strong, hooked and sharp 

 claws Stercorariidae, p. 314. 



Family I. LARIDiE. 



Key to the Subfamilies. 



Bill straight, rather slender, both mandiblea 

 of about equal length (paragnathous) ; 

 pterylosis perfectly Scolopacine ; tail 

 slightly or distinctly forked STUJiyiN.^, p. 4. 



B 2 



