CLASSIFICATION OF BIRDS. 351 



(5) CEdicnemidce (Stone Curlews'). — No hallux; 16 cervical 



vertebrae. 



(6) Parridm (Jacanas). — No British species. 



(ii) Oavice. — Downs of young complex. Front toes webbed. Aquatic. 

 Animal-feeders. Supra-orbital glands large. 



(1) Alcidce (Auks). — Sternum with two notches. Coracoids 



separate. 



(2) Laridce (GuUs). — Sternum with four notches. Coracoids 



touching. 



11. Columbiformes. — Cosmopolitan. Phytophagous (plant • eating). 

 Adult downs restricted to apteria. No lateral cervical apteria. 11 

 remiges. Oil-gland nude or absent. Nares impervious. Crop globular. 

 Sehizognathous. 



(i) Pterocles (Sand -grouse). — Young precocious. Ceeca large. 15-16 



cervical vertebra, 

 (ii) Colwmbce (Pigeons and Doves). — Young nestlings. No downs on 



adults. Ceeca not functional. 14 or 15 cervical vertebras. 



12. Cuculiformes. — Cosmopolitan. Young nestlings. Neck with lateral 

 apteria. 10 primaries. Desmognathous. Sternum with small notches. 

 Feet soansorial. 13, 14, or 15 cervical vertebrie. 



(i) Coccyges. — Nestlings naked. Downs of adults restricted to apteria. 



(1) CiiCiiZid<:E (Cuckoos). — Insectivorous. Cteca large. Oil-gland 



nude. 14 cervicals. 



(2) Musophagidce (Plantain-eaters). — No British representatives. 

 (ii) Psittaci (Parrots). — No British species. 



13. Coraciiformes. — Young nestlings. Feet four - toed. Metatarsus 

 short. Sternum solid or with four notches. 13-15 cervical vertebrae. 

 Nares impervious. Sehizognathous with desmognathous tendency (fig. 

 182, o). 



(i) Siriges (Owls). — Plumage soft. Nestlings downy. Feet and bill 

 raptorial, fourth toe reversible. Downs of adults restricted to 

 apteria. Tibia with a bony bridge for extensor tendons. 14 

 cervical vertebrae. Caeca functional. No spina interna. 



[ii) Macrochires. — Cosmopolitan. 10 remiges ; terminal quill long. OQ- 

 gland nude. 13 or 14 cervicals. Spina interna and externa small 

 or absent. 



(1) Oaprimulgidce (Goatsuckers). — Young nestlings downy. 



Bill broad, wide, and short. Caeca functional. 



(2) Cj^pseZidre (Swifts).— Nestlings naked. Caeca absent. 



(3) TrochUidce (Humming-birds). — No representatives. 

 (iii) Coin (Colies). — No British species. 



(iv) Trogones (Trogons). — No British species. 



