VEETEBRATA 89 



ticulated with skull ; basiptery- 



goids ; (6) HctcroxpondyM. 



Toes free ; vertebrte saddle-shaped ; ros- 

 trum fixed ; (7) Coccygomorphie. 



AAA. First and fourth toes directed backwards 

 (zygodactylous). 



Rostrum freely articulated with the 



skull ; vertebrae opisthocoelous ; (8) Psittaci. 



AAAA. First and second toes directed backwards 

 (heterodactylous). 



Basipterygoids present ; heteropelmous ; (9) Trogonoidei. 



II. Maxillopalatines not united across the palate ; 

 vomer narrowed and acute in front. [Schizo- 

 g)tathfe.) 



A. Toes three forwards (anisodactylous). 

 Schizorhinal ; toes webbed; (10) Cccomorplnr. 



Toes free ; legs long; feathers with after- 

 shaft : prsecoces ; (11) Grallse. 



No basipterygoids ; lachrymal bones co- 

 ossified with rostrum ; toes free ; (12) Opisthocomi. 



Toes free ; hallux rudimental ; (13) Gallhix. 



Toes free ; hallux well developed ; two 



carotid arteries ; (14) PuUastrx. 



Toes free ; hallux well developed ; one 



carotid artery ; basipterygoids ; (15) Micropodioulci* 



AA. First and fourth toes directed backward 

 (zygodactylous). 



* Family Trochilicl:i'. 



