1892.] CLASSIFICATION OF BIRDS. 237 



II. Subclass NEORNITHES. 



Metaccarpals fused with each other. Second finger the longest, 

 third linger reduced. Caudal vertebrae apparently uot more than 

 13 in number. 



1st Division. NEORNITHES RATITiE. 



Nidifugous. Omnivorous. Terrestrial. 



Rhamphotheca compound. Nares impervious. Holorhinal. 



Vertebrae heteroccelous. 



Basipterygoid processes functional. Proximal articulating head of 

 quadrate single. 



Sternum without keel and without spina interna. Spina externa 

 small or absent. Coracoid fused with scapula ; both bones forming 

 a very obtuse angle. 



With incisura ischiadica ; only in adult Rhea and Dromceus the 

 distal end of the ischium fusing with the ilium and forming a fora- 

 men ischiadicum. 



Wings reduced ; flightless. Terminal caudal vertebrae not coa- 

 lesced into a pvgoslyle. 



Hypotarsus simple. Flexors of type II. or IV. 



Adult without pterylae. Oil-gland absent. 



Caeca functional. 



1. STRUTHIONES. 



Ethiopian. 



Maxillo-palatines articulating with the vomer, which touches 



neither palatines nor pterygoids. 

 Third and fourth toes only developed, terminal phalanges 



shortened, with stunted nails. 

 Procoracoid large. No clavicles. Tibia without bony 



bridge. 

 Aftershaft absent. 

 Caeca and rectum enormous. (Unique.) 



2. RHE^. 



Neotropical. 



Maxillo-palatines large, fenestrated, not touching the vomer. 



Palatines short, articulating wiih the vomer. 



Hallux absent. Front toes vrith claws, middle phalanges 



shortened. 

 Procoracoid process large. No clavicles. Tibia without 



bony bridge. 

 Aftershaft absent. 

 Caeca large. 



Syrinx tracheo-bronchial, with one pair of syringeal muscles. 

 {Unique among Ratitce.) 

 Proc Zool. Soc— 1892, No. XVII. 17 



