522 OPHIDIANS. 



FIFTH FAMILY. RATTLE SNAKES. 

 Crotalida, (Gr. xgtiralov, krotalon, a rattle or bell.) 



The Crotaline group, including Rattle Snakes, exhibit the fol- 

 lowing characters : the face has a large pit on each side ; the 

 head is large behind, crown flat, covered with scales or small 

 shields ; the jaws weak, the upper with long fangs in front, and 

 no teeth ; the belly is covered with broad band-like shields, and 

 there are no spurs or rudimentary feet. The species are all more 

 or less venomous ; a part of the family are viviparous, the rest 

 ovo- viviparous. 



The Crotalus, or Rattle Snake, is the type genus of this fam- 

 ily. All the species are distinguished from the others of the 

 group by the presence of a rattle at the end of the tail, (see 

 Chart.) This consists of a number of joints of a horny texture, 

 loosely joined together, so that when rapidly vibrated, they make 

 a distinct whirring noise, which has been compared to that of 

 peas shaken about in a dry bladder, or to the sound produced by 

 the locust, and is heard at some distance. The rattles vary in 

 number according to age; the basal bell or rattle is the last 

 formed and the largest ; one is erroneously said to be added 

 every year. The head is covered with scales, but in one sub- 

 genus with plates. 



Rattle Snakes, especially when irritated, exhale a disgusting 

 odor. The peccary is said to destroy and devour them, as does 

 the common hog also ; but horses and dogs avoid them. They 

 are sluggish and inactive in their movements; and, though 

 highly venomous, seldom attempt to inflict any injury upon man 

 unless molested by him. His approach calls forth the noise of the 

 rattle, which usually precedes any blow. These reptiles never 

 ascend trees, always capturing their prey upon the ground. 

 Usually they rest coiled spirally, in paths, or clear spots in the 

 woods, waiting for their prey, upon which they dart, when 

 within the proper distance. In mid-winter and during hard frosts 

 these serpents intertwine themselves together, in ball-like masses, 

 and become totally torpid. At that season they may be handled 

 without danger. They eat indifferently all kinds of birds, but 

 not frogs, to which the Black Snake is so partial. Their food 

 also consists of small animals, such as rabbits, squirrels, rats, 

 &c., and sometimes even dogs are killed by them. Two or 

 three species of the genus Crotalus are found in North America. 



The COMMON or BANDED RATTLE SNAKE, C. durissus, is dis- 

 persed abundantly throughout the United States, though rarely 



