NATURAL HISTORY. 
113 
ROOM II.] 
Bombinator are hid under the skin ; in Alytes and Pelodytes they are 
exposed. The genera Scaphiopus , Pyxicephalus , and Pelobates have 
a hard horny disk to the hind feet; in the former the toes are webbed, 
and in the two latter they are free. The Oxyglossi are peculiar for 
having no teeth on the palate. 
The family of Toads (Bueonidje, Case ) are only to be distinguished 
from the Frogs by both jaws being equally deprived of teeth, and their 
palate is usually equally toothless. They are generally nocturnal, living in 
holes and under stones, and coming out at night to search for their food, 
which chiefly consists of insects. Their skin is generally warty. Most 
of them have a well developed tubercle at the hinder edge of the hind 
feet, which is produced by a prolongation of one of the wedge-shaped 
ankle bones. The genera Dendrobate and Hylcedactylus are peculiar for 
having the end of their toes dilated like the Tree Frogs; the former is 
slender, and resembles them in shape, and has the drum of the ear visible, 
the latter is smaller, like the Swollen Toads, and have the drum hidden. 
The Toad (Bufo) has the drum of the ear exposed, while in all the follow¬ 
ing genera it is hidden under the skin. The Brachacephyles are pe¬ 
culiar for having the back armed with a long dorsal shield. The Rhi- 
nodermus has the nose ornamented with beards. The Engystomes and 
the Breviceps have the toes free. The Rhinophrynes and Atelopes have 
only four toes on the hind feet. The Plectropodes and Uperodontes 
have two large oblong tubercles on the hind feet, and Phryniscus a 
small round one. 
The second section of this order, or PJuynaglossce, have no distinct 
tongue; it consists of a single family, ( Pipidce ,) one genus of which 
(Pipa ) is peculiar for having the eggs hatched in holes in the skin of 
the back of the male. 
The second order, or Tailed Batrachians, (Urodeles,) have an elon¬ 
gated body, with a more or less elongated tail. They consist of the 
single family of Salamanders ( Salamandrid^e, Case 26.) 
The second section, or Immutabilia , do not undergo any change 
during the period of their lives; they offer several variations in the form 
of their respiratory organs. 
The Batrachophilice , or family of CtECiLiADiE, have no distinct gills, 
or they only have them at a very early period of their lives ; they are 
elongated, snake-like, and destitute of any limbs ; they are said to be 
viviparous. ( Case 26.) 
The Cryptobranchice , or family of Amphiumid^e, have no gills, but 
they have a slit in the side of the neck where the gills are usually 
placed. ( Case 26.) 
The Perennibrachicz , on the contrary, have distinct external gills, 
which they bear during the whole period of their lives, as the Axoloth, 
Menobrachus , Proteus , and Siren . In Case 26 is a wax model of the 
Siren, shewing its appearance when alive. 
1. Mutabilia. 
Ord. 1. Avoura. 
Fam. 1. Hyhtdce. 
a. Litoria. 
b. Acris. 
Lemnodytes. 
Polypedates. 
Orchestes. 
Ixalus. 
Eucnerais. 
Rhacophorus. 
Trachycephalus. 
Hyla. 
Mierhyla. 
Cornufer. 
Hylodes. 
Phyllomedusa. 
Elosia. 
Crossodactylus. 
Phyllobates. 
Fam. 2. Ranida. 
a. Cystignathus. 
Crinia. 
‘^eipherus. 
b. Rana. 
Discoglossus. 
Pseudis. 
__.,.Pe|tocephaIus. • 
Cafyptoeephalus. 
Cycloramphus. 
Leptobrachium. 
c. Ceratophys. 
Phrynoceros. 
