104 



THE NATURAL HISTORY REYIEW. 



The few species of the remarkable genus Denhrolates, constitut- 

 ing this family, are found in the Neotropical region. They are 

 characterized by many peculiarities. The ethmoideum is the most 

 strongly developed in the order ; it is largely produced anteriorly, 

 widely separating the small prefrontalia ; post ero -laterally it fills the 

 entire space between the sphenoideum and parietale, leaving only the 

 foramen opticum. The terminal phalanges support discs, by a trans- 

 verse limb upon the extremity of each, as in Calohyla. There is the 

 usual number of nine vertebrae, the sacral giving attachment to the 

 coccyx by two condyles ; the diapophyses and posterior zygapophyses 

 are connected by a horizontal bony lamina, w^hich gives the dorsal 

 surface of the vertebrae an unusual extent. 



AECIFERA. 



The greater number of the families of this suborder possess, as in 

 the last, dilated sacral diapophyses : the tongue is always free, and 

 never retractile posteriorly. It is, however, particularly interesting 

 as embracing types which offer an approach to the Batrachia gra- 

 dientia in the possession of ribs and opisthocoelian vertebrae. These 

 inhabit exclusively the Palsearctic region, where they were preceded 

 in miocene times by forms, some more completely developed, others 

 quite similar. The representatives of these in the Palaeotropical 

 region do not exhibit such decided salamandrine tendencies, but form 

 a connexion between them, the procoelian Arcifera and the Aglossa ; 

 in the case of the last, by a form common during the Miocene period 

 in Europe, but not at present existing. With a very few exceptions, 

 the remaining types are American and Australian. The six families 

 are distinguishable as follows : — 



I. Sacral diapophyses dilated ; vertebrae opisthocoelian. 



Eibs; diapophyses of first coccygeal vertebra; 



outer metatarsi separated by web .... Discoglossid^. 



No ribs or coccygeal diapophyses; outer meta- 

 tarsi bound together Asterophetdid^. 



II. Sacral diapophyses dilated ; vertebrae procoelian. 



Terminal phalanges continuous, conic, simple . Scaphiopodid-S. 

 Termiual phalanges, with a swollen base, and 



slender, curved, claw-like termination . . . Hylid^. 



