Ambiens muscle present and normal, or present and incomplete, 

 or wanting altogether. 



Deep plantar tendons galline. 



Eggs white. Young helpless, hatched naked, but covered with 

 down before acquiring feathers. 



The affinities of the Parrots seem to be with the Owls and the 

 Birds of Prey. 



The Parrots principally inhabit tropical countries ; but a few 

 species extend as far as 40° or even 42 D N. lat. and 55° S. lat. 



Key to the Families. 



I. Hook of the bill underneath nearly smooth, 



or only with some very superficial longi- 

 tudinal ridges, but with no distinct file- 

 like surface. 



a. Bill longer than deep, much compressed; 



under mandible with the gonys nearly 

 straight, or slanting in a gentle curve 

 towards the tip (see figs. ], '2, p. .'!•. 

 a . Tongiie fringed ; culinen of the bill 



grooved along the middle 



b' . Tongue furnished with a kind of 

 brush ; culmen of the bill smooth, 

 not grooved along the middle .... 



b. Bill deeper than long, much swollen on 



the sides ; under mandible with the 

 gonys strongly curved and abruptly 

 ascending towards the tip (see fig. 3, 

 p 3) ; tongue unrecorded 



II. Hook of the bill underneath with two 



lateral series of ridges, more or less 

 transversal or oblique, producing a file- 

 like surface (see figs. 4, 5, p. 3) ; tongue 

 simple. 



a. Sternum complete. 



a'. Orbital ring complete, with a process 

 bridging the temporal fossa ; head 

 always crested 



b'. Orbital ring mostly incomplete ; if 

 complete, without a process bridging 

 the temporal fossa ; head without a 

 crest, except in the genus Nym- 

 phicus 



b. Sternum incomplete, having only a rudi- 



mentary keel ; orbital ring complete . 



1 . Nestoridae, p. 4. 



2. Loriids, p. 11. 



[p. 86. 

 3. Cyclopsittacidae, 



r P . loi. 



4. Cacatuidas, 



[p. 137. 



5. Fsittacidae, 



[p. 599. 



6. Stringopidae, 



