197 
We now give a short arrangement of the genera 
which have been already proposed by different or- 
nithologists. Those in capitals are what Mr Swain- 
son considers the five leading forms, those in com- 
mon letters are the subgenera, of which one or two 
more will be necessary in both Perdix and Cryp- 
turus. 
The Rasores, or third order of birds, contains the 
families Pavonid®, Tetraonid®, Cracid®, Struthio- 
nid®, Columbid®. 
The family of Tetraonid® contains the genera and 
subgenera 
Perdix. 
Francolinus. 
Ortyx. 
Cotumix. 
Tetrad. 
Lyrurus. 
Centrocercus. 
Lagopus. 
Syrrhaptes. 
Pterocles. 
Attagis ? . 
Cryptonix. 
Ortygis. 
Crypturus. 
