On a group of Psittacidce known to tfie Ancients. 47 



gissimis ; secunda? tertiae et quartae pogoniis externis in medio 



gradatim latioribus. 



Cauda gradata; rectricibus duabus mediis gracillimis caeteras 



longitudine magnopere excedentibus. 



Pedes; tarsis brevibus, debilibus ; unguibus mediocribus, sub- 

 gracilibus, falcatis. 



Corpus gracile, conciiinum. 



Typus genericus. Ps. Alexandri. Linn. 



The birds that compose this genus are at first sight distinguislied 

 by their superiour elegance and gracefulness of form. This cha- 

 racter is considerably increased by the construction of the (ail, 

 the two middle feathers of which far exceed the rest in length. 

 This is a form which decidedly separates the present division of 

 Parrots from all the other known species of the family ; and 

 which has caused M. Le Vaillant to designate by the name of 

 Perroquets a queue enjUche those species of the group which he has 

 figured. The bill is much dilated above, and rounded like that 

 of Platycercus^ but it is somewhat more elongated : the under 

 mandible also, like that of Platycercus^ is short and bent in- 

 wards, but it is not so much bent as in the latter genus, and conse- 

 quently has not so strong an emargination. The wings are of 

 moderate length, the three outward quill feathers beitig the long- 

 est, and nearly equal in length. The outer webs of the second, 

 third, and fourth of these feathers are much dilated in the centre, 

 becoming gradually narrower towards the wpex ; in this construc- 

 tion differing from most of the conterminous genera, in which the 

 same webs are either abruptly emarginated. as in Platycercus and 

 Pezoporus, or entire as in many of the neighbouring long tailed 

 groups. The tarsi axe short, and partially covered by the feathers 

 of the thighs, and the conformation of the legs and feet in general 

 denotes considerable weakness. 



The similarity of colouring that prevails among all the birds of 

 this group, has given rise to much confusion in regulating the 

 species, the greater part of which have been until lately con- 

 sidered varieties of two or three species. Great praise is due to the 



* See Zool, Jouvn. Vol. I. p. 527. 



