1889.] Synopsis of the Families of Vertebrata. 86 
Epanodonta ; Typhlopidai. 
Tortricina ; Tortricidai, Uropeltidae. 
Asinea ; Xenopeltidae, Pythonidae, Boidae, Charinidae, Act 
rochordidae, Nothopsidae, Colubridae, 
Proteroglypha ; Hydrophidae, Najidae, Elapidae, Dendraspididae. 
Solenoglypha ; Causidae, Atractaspididae, Viperidae, Crotalidae. 
AVES. 
There are four superorders of the birds, as follows : 
Metacarpal and carpal bones all distinct, the digits 
with ungues ; caudal vertebrae numerous, un- 
modified ; clavicles united ; pelvic elements 
distinct ; teeth present ; Sa 7irw'<2. 
Metacarpals and carpals coossified ; digits without 
ungues ; caudal vertebrae moderately numer- 
ous, without ploughshare bone; clavicles 
distinct ; pelvic elements coossified ; teeth 
present ; Odontolcce. 
Metacarpals and pelvic elements coossified ; cau- 
dal vertebrae reduced, with a pygostyle or 
plowshare bone ; vertebrae biconcave ; teeth 
present ; Odontotornia. 
Metacarpals and carpals coossified ; pelvic elements 
coossified ; clavicles coossified ; caudal verte- 
brae few, terminating in a plowshare bone ; 
vertebrae mostly saddle-shaped ; no teeth ; Eiirhipidurce. 
The SAURUR.E includes but one order, which is defined as 
Vertebrae biconcave; feathers arranged in one 
series on each side of the caudal vertebr.-E ; Oniithopappi. 
To this order but one family belongs, viz., the Archa^^optery- 
gidae. 
The superorder Odontolc^ includes also but one order. 
Teeth in a grove ; sternum without keel ; wings 
rudimental ; pelvic bones free posteriorly ; DromcEopappt. 
The Drom^opappi has but one family, the Hesperornithidae. 
