210 ZOOLOGY. 



take turns in sitting on them. The nest may be left un- 

 covered during the heat of tlie day, but in this region 

 (Buenos Ayres), I beheve, it is never entirely deserted. 

 (^American Naturalist, July, 1883.) 



Ordbrs op Carinate Birds. 



1. "Wings small and short; diving birds Pygopodea. 



2. Wings long, pointed; rapid fliers; anterior toes 



webbed Lnngipennes. 



3. Feet whoUjr webbed, including the inner toe Stegopodes. 



4. Bill lamellate, i.e., both mandibles with teeth-like 



projections Lamellirostrea. 



5. Wading birds; the leg long and naked above the 



heel ; bill usually long and slender Grallatores. 



6. Land birds; four toes, three in front, one behind; 



tibiae often spurred Qallina. 



7. Toes like the foregoing; the bill horny and convex 



at tip Columbm. 



8. Bill cered, hooked, and large; feet large, not yoke- 



toed Raptores. 



9. Feet yoke-toed; bill stout, and strongly liooked. . .PszHacz. 



10. Toes often in pairs, two in front and two behind; 



wings with ten primaries Picarim. 



11. Perching and singing birds; feet adapted for 



grasping; bind toe opposed to the others Passeres. 



Sub-Class I. — CARiNATiE. 



General Characters of Carinate Birds. — All other living 

 birds belong to this group; they are remarkably homogene- 

 ous in form and structure. They are characterized by the 

 keeled breast-bone or sternum — the wings, as a rule, being 

 well developed. 



Order 1. Fyfjoj'iodcs (Diving birds). — These are eminent 

 as swimmers, and comprise the penguins, auks, puffins, 

 grebes, and loons. The penguins (Figs. 246, 247) are con- 

 fined to tlie antarctic regions. They ai-e lai-ge birds, and 

 form a characteristic element in a Patagoiiian landscajie. 

 The bones are solid, not light and hollow, as in other birds; 

 the wings are small, paddle-like, with scale-like feathers; 



