184 5 CYSTIGNATHIDE, 
one of the highest degrees of cranial ossification which a Frog can 
attain. 
The auditory organ exhibits all the possible degrees of develop- 
ment. Several genera, viz. Crinia, Hylodes, &c., prove that too 
great an importance has been attached to the modifications of this 
organ, and in most cases I must refuse to admit them as generic 
characters. 
The distal phalanges are simple, or with divergent terminal pro- 
cesses. 
Most of the Australian representatives of this family, and a few 
of the American, have the pupil erect. 
The Cystignathide include arboreal, aquatic, terrestrial, and 
burrowing types. 
Synopsis of the Genera. 
I. Outer metatarsals completely separated; sternum without 
bony style; toes webbed. 
Pupil horizontal ; first finger opposite to the others; tongue circular. 
1. Pseudis, p. 185. 
Fingers webbed; tips of fingers and toes dilated into large disks. 
2. Centrolene, p. 187. 
Pupil erect; tongue circular ; tympanum distinct. 
3. Mixophyes, p. 188. 
Tongue oval; tympanum hidden .. 4. Cyclorhamphus, p. 189. 
II. Outer metatarsals united or incompletely separated. 
A. Sternum without bony style; toes webbed. 
Pupil horizontal; head rough, entirely bony, the orbit completely 
enclosed ; tongue entire ........ 5. Calyptocephalus, p. 189. 
Pupil horizontal; derm of head free from cranial ossification ; 
HOMERS CMI V4 oats sc hse ev eee 6. Telmatobius, p. 190. 
Pupil horizontal ; tongue nicked behind. 
10. Ceratophrys, p. 221. 
Pupil vertical; first finger opposite to the others; diapophyses of 
sacral vertebra slightly dilated .. 23. Chiroleptes, p. 267. Y 
Pupil vertical: tympanum concealed; diapophyses of sacral vertebra 
slightly dilated” 2% . sk eee ee 24. Heleioporus, p. 271. 
B. Sternum without bony style; toes free, or nearly so. 
1. Tips of fingers and toes dilated into regular disks; pupil 
horizontal. 
Vomerine teeth ; digital disks divided on their upper surface by a 
BNOOVE YT ios ed aries 7. Elosia, p. 193, 
