/)i'/)li/cs (iikI Aiiiphih/diis (if ////iioifi. 317 



ing in Africa, South America, and Ceylon has small embedded 

 scales, and is further characterized by absence of limbs and 

 tail. 



liody of adult stout, short. Hind legs suited to leaping and 

 swimming. No tail. Frogs and toads Order Anura. 



Body long and slender. Hind legs not enlarged for leaping 

 and swimming, sometimes wanting. Tail and sometimes 

 branchi;i! persistent. Salamanders Order Uuodela. 



ORDER ANURA. 

 (Amphibia Ecaudata, Theriomorpha, Batrachia.) 



Body stout, short, more or less depressed. With two pairs 

 of legs, the anterior of which bear four, and the larger posterior 

 pair five, digits. Mandible generally toothless. Adults tailless. 

 Vertebral column composed of but few vertebne and terminat- 

 ing in a long solid coccyx — the urostyle. Sternal arch complete. 

 Kadius and ulna fused. Tibia and fibula also fused. The two 

 proximal tarsal bones very long and often fused at their 

 extremities. 



The adults are known as frogs and toads. They move on 

 land by lea]is, the structure of the posterior legs being specially 

 suited to this mode of locomotion. In water they use the same 

 legs for swimming. The food consists chiefly of small inverte- 

 brates, insects constituting the greater part of it. The young 

 are known as pollywogs and tadpoles. They are fish-like, liv- 

 ing in water, in which they swim with the aid of a tail, and 

 breathing by means of branchiae. Instead of teeth they pos- 

 sess horny jaws. At this stage of their lives they subsist 

 chiefly on vegetable substances, such as filamentous Algae, 

 diatoms, desmids, etc. 



SYNOPSIS OF THE FAMILIES REPRESENTED IN ILLINOIS. 



1 (2). Fingers and toes with no evident discs at their tips. 8. 



2 ( 1 ). Fingers and toes with evident discs 7. 



8 (4). Upper jaw with teeth. No overlapping sternal 



cartilages ; omosternum and sternum present. 

 Transverse processes of sacrum subcylindrical. 



Ranid^. 



