1-srTTACID.E. 



137 



Family V. PSITTACIDiE. 



It is extremely difficult to defiue the PsittacidcB by positive cha- 

 racters. They are separated from the Stringopidce by having a 

 complete sternum, from the Nestoridee, Loriidce, and Oyclopsittacidce 

 by the file-like surface on the palatine portion of the hook of the bill, 

 and from the Cacatuidce by the absence of a crest (except in Xym- 

 pkicus). 



They occupy a very extensive area, being distributed all over 

 the intertropical regions : they are the only Parrots found in the 

 Neotropical, the southern part of the Nearctic, and the ./Ethiopian 

 regions; in the Eastern Oriental region they meet -with the Caca- 

 tuidce, and in the Australian they are found associated with all the 

 other families. 



Key to the Subfamilies. 



a. Tail spined ; size very small : females 



different from the males 1. 



b. Tail soft. 



a . Furcula present (except in the genera 

 Psittacula and Ayapornis). 

 a". Left carotid superficial. 



a"'. Orbital ring often complete; 

 plumage mostly green. 

 (i 1 . Tail rather long", generally gra- 

 duated and cuneated -. 



b\ Tail moderate or short, not cu- 

 neated ; cere always naked . . 3. 

 b". Orbital ring alwavs incomplete; 

 plumage grey or black, partially 

 red or with no red at all ; sides 

 of the head more or less naked ; 

 tail-feathers never acuminate ; 



bill never red 4. 



b". Left carotid normal, like the right 

 one running in the hypoapophysial 

 canal; orbital ring always incom- 

 plete ; sides of the head feathered, 

 if naked, only immediately round 

 the eyes; tail-feathers frequently 

 acuminate ; bill often very strong, 

 and, especially the upper mandible, 

 frequently red : females mostly dif- 

 ferent from the males 5. 



b'. Furcula absent; orbital ring incomplete; 

 tail rather long, graduated, often 

 broad ; bill moderate, never red .... 6. 



[p. 138. 

 XASITERXIXA?, 



COXURIXA?, p. 145. 

 PIOXIX.E, p. 267. 



PSITTACIXA?, p. 376. 



p. :jsrt. 

 PALA^OEXI TBINJB, 



[p. 539. 

 PLATYCEltCI\.E. 



