COPE ON THE B.\.TRACHIA SALIENTIA. 101 



are developed to their fullest extent, forming complete sutures with 

 each other and with the parietale. In the second, these bones are 

 separated widely or partially by the exposed superior plate of the 

 ethmoid, which may be principally cartilaginous (^BrachycepJialus) , 

 a broad bony area {BJiinode^'md)^ or strongly ossified in the form of 

 the nose-piece of a helmet, to the end of the muzzle (Atelopus, sp.). 

 Of these three genera the first has the ear imperfectly developed ; in 

 species of the third the epicoracoidei are not in contact with the 

 coracoidei, but have a very short, simple, cartilaginous connexion. 

 There are also but eight vertebrae in some of the species, the atlas 

 being confluent with the first, and in A.fiavescens the coccygeal con- 

 dyle is single (transverse). This peculiar group is confined to the 

 Neotropical region, where it represents, in the structure of its skulh 

 the typical group of CystignathidcB among the Arcifera, and Dendro- 

 hatidcej from which it is not far removed in affinity. 



In the first section, Micro-hyla exhibits an imperfectly developed 

 ear. Caloliyla (= Holonectes and Flectropus), and Micro-Jiyla have 

 digital dilatations similar to those of the Tree-Frogs ; their terminal 

 phalanges are furnished with a terminal transverse limb, which is 

 most noticeable in the first-named genus, and similar to the structure 

 in Hylarana, but difierent from those in Folypedates and Hyla, 

 Cacopus, Gthr. (Hyperodon), auct.), Diplopelma, and Micro-hyla are 

 the only genera in the family without o. epicoracoidea. JEngystoma 

 and Calophry7ie are the remaining genera, the former the only one 

 which is not confined to the Palseotropical region : it is both North 

 and South American. In the latter the coccyx is articulated to the 

 sacrum by a single transverse condyle ; in all the other genera it is 

 double. In their completely developed parietal and fronto-nasal 

 bones, the genera of this section resemble the types of aquatic 

 ManidcB of the same region. The xiphistemum is either entirely or 

 basally fibro-cartilaginous ; in the three genera of the secoud division 

 it is thin and cartilaginous. 



Brachymeeid^, 



Superior plate of ethmoid not ossified, either medially or wholly 

 cartilaginous or fibro-cartilaginous. Epicoracoids divergent from 

 coracoids, and connected with them by a single or double narrow 

 cartilaginous band, the latter in contact with each other i* no ma- 



* Not observed in Braclujmerus. 



