COPE ON THE BATBACHIA SALIENTTA. 109 



which is of a more compact tissue. O. fronto-parietaKa shortened 

 anteriorly, usually embracing a fontanelle. Superior plate of eth- 

 moid never covered by fronto-parietals, usually produced anteriorly, 

 between fronto-nasals. Ear perfectly developed. 



This family embraces the Tree-Progs of the New "World and 

 Australia, though in the latter country, with its usual perverseness, 

 they are terrestrial in their habits. One species is found in the Old 

 World, viz. B^yla arborea of the Fauna Palsearctica. 



There are fifteen genera in this family, of which five want the 

 parietal fontanelle. In two the prefrontals are in contact. The 

 xiphisternum is usually a parallelogrammic fibro-cartilaginous plate, 

 deeply emarginate posteriorly, and divided by an imperfect longitu- 

 dinal suture in two halves ; or it is entirely cartilaginous, as in Pseu- 

 dacris. The manubrium is slightly developed, usually cartilaginous, 

 rarely apparently wanting. The following is a sketch of the 

 genera: — . . 



I. No fronto-parietal fontanelle. 



a. Head covered with a dermo-ossification. 



A dorsal dermal pouch Opistliodelphys. 



No pouch ; prefrontals in contact anteriorly TracliycepTialus. 

 aa. Head without dermo-ossification. 



No pouch; prefrontals large, in contact 

 medially their entire length. No paro- 

 toid Acrodytes.^ 



No pouch. Prefrontals in contact. A paro- 



toid covering head and back .... Scytopis. 



A dermal pouch ; toes slightly webbed . Nototrema. 



II. A fronto-parietal fontanelle ; the prefrontals separated by the 



horizontal ethmoid plate. 



a. Parotoid glands present. 

 Parotoid on scapular regions. Interior 



digits not opposable Felodryas. 



Interior digits opposable. Poot without 



web ; tongue elongate, free . . . » . JBliyllomedusa. 

 aa. No parotoid glands. 

 h. Toes webbed. 



* Type B%jla vcnulosa, Daudin. 



