1889.] 
Synopsis of the Families of Vertebrata. 
871 
The Ptilopteri includes the single family of the Aptenodytidae 
or penguins. 
The EuoRNiTHES include numerous suborders, which are defined 
as follows: 
I. Maxillopalatines united across the middle of the palate. 
{DesmognatJKB). 
A. Four toes directed forwards (pamprodactylous). 
Toes webbed ; no basipterygoids ; Steganopodes. 
Toes free ; vomer unossified ; no basipterygoid 
processes ; Colioldei. 
A A. Three toes directed forwards/ 
Short basipterygoid processes ; toes generally 
webbed ; praecocial ; ChenomorpJuB. 
No basipterygoid processes ; bill and legs slender ; 
toes generally free ; altricial ; Herodii. 
Bill and claws hooked ; toes free ; altricial ; ver- 
tebrae saddle-shaped ; Accipitres. 
Bill hooked ; toes free ; vertebrae opisthocoelous ; 
rostrum movably articulated with skull; 
basipterygoids ; Heterospondyli. 
Toes free ; vertebrae saddle-shaped ; rostrum fixed ; Coccygomorph4Z. 
AAA. Two toes directed forwards and two backwards. 
Rostrum freely articulated with the skull ; ver- 
tebrae opisthocoelous ; Psittaci. 
II. Maxillopalatines not united across the palate ; vomer nar- 
rowed and acute in front. {Schisognath(s) 
A. Toes three forwards (anisodactyl'ous). 
Schizorhinal ; toes webbed ; CecomorpJuB. 
Toes free ; legs long ; feathers with after shaft ; 
praecoces ; 
No basipterygoids; lachrymal bones coossified 
with rostrum ; toes free ; 
Toes free ; hallux rudimental ; 
Toes free ; hallux well developed ; two carotids ; 
Toes free; hallux well developed; one carotid 
artery; basipterygoids; Microp^ 
Gralla. 
Opisthocomi, 
Gallince. 
PullastriB. 
