5O THE CLASSIFICATION OF BIRDS 



28. PSOPHLE. 



The PsophiaB consist of three South American families and 

 one African and Indian family, differing very widely from each 

 other. The Opisthocomidce are in some respects the most aberrant 

 of birds : the sternum looks as if the keel had' been turned upside 

 down, the posterior half projecting more than the anterior portion. 

 Neither the Opisthocomidce, the Podicidce, nor the Cariamidce have 

 lateral bare tracts on the neck. The subclavicular process is very 

 large in the Opisthocomidce, the Podicidce, and the Psopliiidce, but 

 only rudimentary in the Cariamidce. The Opisthocomidce and the 

 Podicidce are said to be altrices, but the Psophiidce and the Caria- 

 midce are supposed to be praecoces. In the Podicidce the toes are 

 narrowly margined with a lobe.* 



29. GALLI. 



The Galli consist of three well-marked families. The Pha- 

 sianidce and the Cracidce have the oil-gland tufted (except in 

 the genus Argus, which has no oil-gland) ; the Megapodiidce -f- 

 have the oil-gland nude. The Cracidce and the Megapodiidce have 

 the hallux oh the same level as the other, digits, and its basal 

 phalanx is as long as. that of the third digit. The Phasianidce 

 have the hallux raised above the level of the front digits, and its 

 basal phalanx is shorter than that of the third digit. In the 

 Phasianidce the inner notch on the posterior margin of the sternum 

 is more than half the. length of the whole sternum ; in the other 

 two families it is less. 



The Phasianidce are almost cosmopolitan; the Cracidce are 

 confined to tropical America ; whilst the Megapodiidce are found 

 in Australia, New Guinea, and other more or less contiguous 

 islands. 



* Lobed feet appear to have been independently acquired by various genera. 

 They are found in all the Podicipidce, in Phalaropus amongst the Charadriidce, in 

 Fulica amongst the Rallidce, in Podica amongst the Psophias, and in Hdiornis 

 amongst the Fulicariae. 



t It has been Stated that the Megapodes have lost the fifth secondary. 

 After very careful examination I can find no evidence in support of the 

 statement. 



