XX ORIENTATION 



Order 2: Anura (Salienta) 



The frogs and toads. Short compact body; tail absent in adult; only nine 

 vertebrae present; ribs ankylosed to vertebrae as short processes; hind legs 

 long and muscular. 



Examples: Ascaphus truei, Scaphiopus holbrookii, Bufo americanus, Rana 

 pipiens, R. sylvatica, R. catesbiana, Hyla crucijer, Discoglossus pic t us, Xe no- 

 pus laevis, Pipa pipa, Nectophrynoides vivipara. 



Order 3; Gymnophiona 



The caecilians are long-bodied, limbless amphibians resembling earthworms. 

 They are inhabitants of the tropics with the exception of Madagascar. Scales 

 are present in the dermal layer of the skin. 



Examples: Hypogeophis alternans, Scoleconiorphus uluguruensis, Caecilia 

 tentaculata. 



3. Class: Re pt ilia 



Scale-covered, cold-blooded, claw-digited vertebrates with a three- or four- 

 chambered heart, and generally inhabitants of dry land or streams. External 

 respiration carried on exclusively by means of lungs. 



Order 1 : Crocodila 



The crocodilians include the alligators and crocodiles. These are large 

 greatly elongated reptiles covered with scales and bony plates. The eye has 

 an upper and lower lid and a nictitating membrane. Teeth are thecodont. All 

 species are oviparous. The anus is a longitudinal opening. 



Examples: Alligator mississippiensis and Crocodylus acutus. 



Order 2: Lacertilia 



The lizards are elongated reptiles of diverse sizes. Teeth are pleurodont or 

 acrodont. The eye has an upper and lower eyelid and a nictitating membrane. 

 The tympanum is not at the surface, and the ear opening may be covered by 

 scales. A vestigial pineal or median eye is often present, and the tongue is 

 well developed and protusile. Most species are oviparous, a few are ovovi- 

 parous, and some may be classed as viviparous. The anus is a transverse slit. 



Examples: Anolis carolinensis, the chameleon; Sphaerodactylus notatus, 

 the reef gecko; Phyrynosoma cornutum, the horned toad; Heloderma sus- 

 pectum, the Gila Monster; the Tuatera of New Zealand, and the dragon lizard 

 of the Dutch East Indies. 



Order 3: Serpentes 



Snakes are crawling reptiles who have lost their legs. They form a large 

 number of reptilian species. Acrodont teeth always are present. Functional 



