110 THE NATURAL HISTOET EEVIEW. 



c. Inner finger not opposite the others ; fonta- 

 nelle broad ; superior ethmoid plate usually 

 with a supraorbital angular dilatation. 



d. Inferior palpebra reticulate with 

 fibrous veins. 

 Tongue elongate, extensively free . . . Agalyclmis.^ 

 dd. Inferior palpebra transparent. 



e. Tongue little free posteriorly, entire 

 or nearly so. 

 No vomerine teeth or cranial ridges . . . Sylella, 

 No cranial ridges ; vomerine teeth . . . Hyla. 

 Two longitudinal cranial ridges ; vomerine 



teeth Osteocephalus.^ 



ee. Tongue extensively free and deeply 

 notched behind. 



Digital dilatations small Aeris. 



cc. Inner finger opposite others ; ethmoid plate 

 not dilated j fontauelle narrow. 

 Litoria. 

 bh. Toes free ; dilatations small ; fontanelle wide. 

 Superior ethmoid plate osseous .... iPseudacris. 

 Superior ethmoid plate cartilaginous ; pre- 

 frontals well developed, in contact me- 

 dially Thoropa.X 



Of these genera Felodryas is Australian ; Litoria and Syla are 

 common to that and the Neotropical region ; Acris and Fseudacris 

 are confined to the Nearctic. The other genera are Neotropical ; 

 Hyla only being represented in the Nearctic and Palsearctic regions. 



CxSTiaNATHIDJE. 



Vertebrae proccelian ; sacral diapophyses cylindrical ; coccyx 

 simple, attached to two condyles. External metacarpi usually bound 

 together. Terminal phalanges continuous, either uniformly conic or 

 with divergent terminal processes or their rudiments. Manubrium 



* Embraces Ifyla vioreletii, Dum., H. Iiolochlora, Salvin, and H. callidryas, Cope. 



f I am not acquainted with the stnictui-e of the skull of these species from 

 examination. 



X Contains the Cystignathus misiessii (Bibr., Voyage de la Bonitc, i. p. 148), 

 from Rio de Janeiro. 



