234 VERTEBRATE ANIMALS OP SOUTH CAROLINA. 



ALCID^. 

 ? C OMMON PUFFIN. Fratercula arctica, (Linnt") Steph. 



CLASS REPTILIA. REPTILES. 



Air-breathing vertebrates with cold, red blood. Exoskeleton developed 

 as scales (serpents and lizards), or horny or bony plates (tortoises). Limbs 

 absent (serpents), or present and adapted for walking and swimming. 

 Eggs hatched externally (oviparous reptiles), or in the body of the parent 

 (ovoviviparous reptiles). 



A large class of useful (tortoises) and baneful animals, remarkable for 

 their varied modifications of structure. Many species which are per- 

 fectly harmless, and possess great interest for the unbiased observer, are 

 commonly regarded with an aversion kept alive by the fables of folk-lore. 

 Aljout two hundred and sixty species are North American. Five orders 

 are usually recognized. 



ORDER OPHIDIA. SERPENTS. 



Reptiles of an extremely attenuated form, devoid of limbs (rarely 

 possessing rudiments of hind limbs), and with the two halves of the 

 lower jaw united by ligament. Right and left lungs unequally developed. 

 Exoskeleton in the form of scales. Oviparous. 



This order includes some of the most venomous of all animals. Only 

 two poisonous families, however, are represented in the United States, 

 namely, the rattlesnakes {Crotalidse), and the harlequin snakes {Elapidee). 

 All other North American snakes, except five species, belong to the great 

 family Colahrixhe, and are perfectly harmless. About one hundred and 

 thirty -two species of this order inhabit North America. 



