64 



GUIDE TO REPTILES AND AMPHIBIANS. 



Fig. 63. 



vertebras. There are four front toes. Owing to the absence of ribs, 

 Frogs, like other Amphibians, can only breathe by swallowing air. 



The order is divisible into three main groups, the first of which, 

 forming the section Firmisternia, includes the Typical Frogs, or 

 Banida' (480-493), the Dendrobathhr (499-500), Engystomatid(C 

 (494-498), and Dysco2)]udce, (401, 402). All these are character- 

 ised by the presence of a tongue and by the union of the two 

 inferior bones of the shoulder-girdle, or coracoids, in the middle 

 line of the chest to form a firm bar. In the Eanidm the trans- 

 verse processes of the sacral vertebra form simple rods, and 

 there are typically teeth only in the upper jaw, although in 

 Giinther's Frog {Ceratohatraclius (imntheri, 490) of the Solomon 

 Islands, these are developed in both jaws. The Dendrohatidcc have 

 both jaws toothless. The Eiigystomatidce and Dyscophidce differ by 

 the expanded sacral transverse processes. In the former teeth are 

 lacking in both jaws, but in the latter they are developed in the 

 upper one, while in Genyophrys, which may represent a family, the 

 lower jaw is alone toothed. Some RanidcB, like Bhacoi^liorm (491), 

 are arboreal and have adhesive toe-pads and webbed feet, but it is 



untrue that they use the latter as a 

 parachute. Certain species deposit their 

 eggs enveloped in foam in mud or grass 

 on the banks of ponds. Many kinds of 

 Rana, like the Bull- Frog, have internal 

 or external dilated vocal sacs. All the 

 American Dendrohatidce, live in trees. 



The largest representative of the 

 group is the huge Rana gifppyi (483), 

 of the Solomon Islands ; of this Frog 

 both the mounted skin and the skeleton 

 are shown. Another well-known, al- 

 though much smaller, species of which 

 a specimen is exhibited is the Indian 

 Tiger-Frog, R. tigrina (487)- The 

 Common Frog {R. temporaria, 482), the 

 continental Edible Frog {R. esmdenta, 

 485), ^ud the American Bull-Frog 

 {R. cateshiana, 488), are also shown in 

 the case. 



The Toads {Bufonid(e, 413-420) may be regarded as the typical 

 representatives of the section Arcifera, which also includes the 

 families DiscoglossidcB (435-439), PeloMUdm (440-442), Hylidm 



Bones of the chest of Goliath 

 Frog (Leptodacfylus penta- 

 dactyhis) to show structure 

 characteristic of the Toad 

 group. 



