SCYTALUS. REPTILES. 361 



forked ; a hollow behind the nostrils ; upper maxillary bones 

 with isolated fangs ; plates or transverse bands under the 

 body and tail ; extremity of the tail with a rattle formed of 

 hollow, moveable, and sonorous plates. 



This group is celebrated for the active nature of the poison they communicate. 

 They have, as the Boas, simple transverse plates under the body and tail ; but what 

 distinguishes them chiefly is the hollow moveable scales at the termination of the tail. 

 This rattle, as it is called, is formed of horny plates, which sound when the animal 

 crawls or moves its tail. The number of these plates augment with age, and they 

 acquire an additional one at each shedding. All the species of which the country 

 is known come from America. Rattlesnakes creep slowly, and never bite unless 

 provoked, or to kill their prey. Although they rarely climb trees, their principal 

 food is birds, squirrels, &c. Tt has long been supposed that they had the power 

 of fascinating small animals, or overpowering them by their breath. The agi- 

 tation and terror of the birds, however, and anxiety to lead the snake from their 

 young brood or nests, by provoking his attention, are sufficient to account for the 

 observed fact, without the necessity of having recourse to a particular and mysteri- 

 ous power of fascination. 



* Scales of the head and back similar. 



C. horridus, Lin. The Rattlesnake. Body brown, with transverse 

 irregular blackish bands ; extremity of the tail black. 4 to 6 

 feet long. Inhabits America. Shaw, iii. pi. 88. 



C. durissus, Lacep. The Striped Rattlesnake, Body brown, with 

 lozenge-formed spots bordered with black, and four black lines 

 along the top of the neck. 5 feet long. Inhabits Guiana. 

 Shaw, iii. pi. 89, 90. 



Both these species are equally dangerous, and their bite causes death in a few mi- 

 nutes. The poisonous fangs, even when withdrawn from the animal, have been 

 known to retain the power of inflicting fatal wounds for years. 



** Head furnished with large plates. 



C. miliaris, Lin. Body gray brown, with a red line along the 

 back, interrupted by a series of black spots, bordered with white ; 

 sides and under parts with smaller spots. 2 feet long. Inhabits 

 Carolina. Catesby, Car. ii. pi. 42. 



Gen. 21. SCYTALUS, Latr. 



Body and tail below with a row of transverse plates ; poisonous 

 fangs in the upper jaw ; no hollows behind the nostrils ; tail 

 destitute of rattles. 



S. ziczac, Daud. (Boa horatta, Shaw.) Body dark brown, with 

 a waving yellow band on each side, and a row of yellowish dor- 

 sal spots, edged with black ; head with four dark spots. 15 in- 

 ches long. Inhabits India. Shaw, iii. 359. 



kGen. 22. AcA^Trfopms, Baud- 

 With double plates under the tip of the tail, which is terminat- 

 ed by a pointed spur ; large plates on the anterior part of 

 the head ; no hollows behind the nostrils ; poisonous fangs 

 in the upper jaw ; hind part of the head tumid, and with 

 scales similar to those of the back. 



