THE VIPERS 2603' 



zigzag cross bands, and are gradually lost on the dark tail, the under parts being 

 yellowish white, marked with small black dots. Generally about four and one-half 

 feet in length, this species may grow to six feet. 



In the Southern United States the commonest member of the genus 

 1 " is the diamond rattlesnake (C. adamanteus) , represented in the upper 



snake figure of the following illustration, which is not only the most 

 beautiful, but likewise the largest species, adult females (which in this 

 group are always larger than the males) not unfrequently measuring six feet in 

 length. From the common rattlesnake it may be distinguished by the large and 

 narrow head, on which the shields are but slightly developed, the presence of three 

 pairs of shields between the rostral and supraocular on the top of the muzzle, by the 

 scales of the body being always arranged in twenty-seven rows, and also by the col- 

 oration. The small rostral shield is markedly triangular, the slightly developed 

 frontal has a roundish pentagonal form, and the great supraocular shield a dis- 

 tinctly overhanging edge. After shedding, the new skin is of a beautiful greenish, 

 or occasionally golden-brown ground color; upon this is a triple of lozenge-shaped 

 chain pattern on each side of the back, the golden yellow lines of which stand out 

 in marked contrast to the dark diamonds of the ground color. A blackish-brown 

 band runs from the muzzle through each eye to the corner of the mouth; and the 

 top of the head is either uniformly colored, or ornamented with irregular markings. 

 Of the six species of the genus, four are confined to North America, 



and only one is found to the southward of the Isthmus of Panama, 

 ican Rattle- 

 snakes The l atter species (C. horridus), which is represented in the lower 



figure of our illustration, approaches the common species as regards 

 the arrangement of the shields on the head, while in coloration it is like the dia- 

 mond rattlesnake. From the former it may be distinguished by the circumstance 

 that the two pairs of shields between the rostral and the supraocular have no small 

 shields between them, so that they come in contact with one another in the middle 

 line; while from the latter the larger size of the lozenges on the body, and the pres- 

 ence in each of a light colored centre will serve as a sufficient distinction, in addi- 

 tion to the different arrangement of the head shields. 



In noticing the habits of these snakes our remarks will chiefly relate 



to the North-American species. As we have already said, rattle- 

 snakes chiefly frequent dry and sandy localities, more especially when they are cov- 

 ered with bushes; but we have to add that in North America they frequently take 

 up their abode in the burrows of the prairie marmot. Formerly it was thought 

 that the snakes and marmots lived together in harmony, but it is now ascertained 

 that the former prey on the young of the latter. The general food of rattlesnakes 

 consists of small mammals, birds, lizards, and frogs, the latter being especial favor- 

 ites; but mammals as large as a mink have occasionally been taken from them. 

 The most extraordinary peculiarity connected with the common species is its habit 

 in the colder regions of North America of collecting in enormous numbers for the 

 winter sleep. In some districts the snakes used to assemble in hundreds, or even 

 thousands, from all sides to sleep in the ancestral den, some of them, it is said, 

 traveling distances of twenty or even thirty miles. Huddled together in masses for 



