CLASSIFICATION OF BIRDS. 351 



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



vertebrse. 



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



(ii) Gavice. — 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 (Gulls). — Sternum with four notches. Coracoids 



touching. 



11. Columbifoimes. — Cosmopolitan. Phytophagous (plant = eating). 

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

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

 Schizognathous. 



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



cervical vertebrae, 

 (ii) Colv/nibce (Pigeons and Doves). — Young nestlings. No downs on 



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



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

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

 Feet scansorial. 13, 14, or 15 cervical vertebrse. 



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



(1) CW«Zi(icE (Cuckoos). — Insectivorous. Caeca large. OU-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. Schizognathous with desmognathous tendency (fig. 

 182, c). 



(i) Striges (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. Oil- 

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

 or absent. 



(1) Oaprimidgidce (Groatsuckers). — Young nestlings downy. 



Bill broad, wide, and short. Caeca functional. 



(2) Oypsdidce (Swifts). — Nestlings naked. Caeca absent. 



(3) TrochiZidce (Humming-birds). — No representatives, 

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



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



