2 4 o SNAKES. 



as a lateral remnant of the hinder frontal. The space between the two last-named 

 shields is occupied by a series of small shields, of which the front ones are the 

 largest; and between the supraocular shields commence the long keeled scales 

 covering the body, where they are arranged in from twenty-five to twenty-seven 

 longitudinal rows. The ground-colour of the upper surface is a dull greyish brown, 

 upon which are two rows of large, irregular spots, which may unite into zigzag 

 crossbands, and are gradually lost on the dark tail ; the under-parts being yellowish 

 white, marked with small black dots. Generally about 4£ feet in length, this 

 species may grow to 6 feet. 



Diamond In the Southern United States the commonest member of the 



Rattle-snake, genus is the diamond rattle-snake (C. adamanteus), represented in 

 the upper figure of the accompanying 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 6 feet in length. 

 From the common rattle-snake 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 coloration. 

 The small rostral shield is markedly triangular, the slightly developed frontal has 

 a roundish pentagonal form, and the great supraocular shield a distinctly over- 

 hanging edge. After shedding, the new skin is of a beautiful greenish, or 

 occasionally golden-brown, ground-colour; upon this is a triple 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-colour. 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 coloured, or ornamented with irregular markings. 

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



Rattle- snakes. America, and only one is found to the southward of the Isthmus of 

 Panama. The latter 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 diamond rattle-snake. 

 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 presence in each of 

 a light-coloured centre will serve as a sufficient distinction, in addition 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 covered with bushes ; but we have to add that in North America they fre- 

 quently 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 

 rattle-snakes consists of small mammals, birds, lizards, and frogs, the latter being 

 especial favourites ; but mammals as large as a mink have occasionally been taken 



