862 The American Naturalist, [October, 
chidae ; Amblystomidae ; Hynobiidae; Plethodontidae ; Thorii- 
das ; Desmognathidae ; Salamandridae ; Pleurodelidae ; Amphi- 
umidae ; Caeciliidae. 
The Trachystomata includes only the family of the Sirenidse. 
SALIENTIA. 
The Anura has the families arranged under the following sub- 
Internal nostrils opening together on the middle 
line; no tongue; coracoids connected by a 
cartilage on each side ; Aglossa. 
Internal nostrils separate ; a tongue ; coracoids 
connected by a separate cartilage on each 
side ; Arcifera. 
Internal nostrils separate ; a tongue ; a single 
median cartilage connecting all the coracoids ; 
scapular arch free ; Firmisternia. 
As in Firmisternia, but scapular arch articulated to 
skull ; Gastrechmia. 
(Aglossa) : Xenopidai ; Pipidai. 
(Arcifera): Discoglossidae ; Bufonidae; Dendrophryniscidae; 
Asterophydidae; Pelodytidae; Scaphiopidae ; Hylidae ; Cys- 
tignathidae ; Amphignathodontidae ; Hemiphractidae. 
(Gastrechmia) : Hemisidae. 
(Firmisternia) : Engystomidae ; Phryniscidai ; Dendrobatidae ; 
Cophylidae; Dyscophidae ; Colostethidae ; Ranidae ; Cera- 
tobatrachida;. 
MONOCONDYLIA. 
There are two subclasses of Monocondylia. 
Anterior limbs ambulatory, with numerous carpal and 
metacarpal bones ; two aorta roots ; integument 
consisting partly of scales ; Reptilia. 
Anterior limbs volant, with the carpals and metacarpals 
more or less coossified and reduced in numbers ; in- 
tegument consisting in part of feathers ; one aorta root • Aves. 
