388 



VEUTEBRATA. 



lli..>i- .lim-lo.l to prevent iiii? the poison from ffcttinu int.. tlir circuhition, and of these the prin- 

 cipal .-onsist in su.-kin,u thi«"woun(i— citlur witli a riii.i.ing-fi;la.ss or with tlio ni.-ulh, which may 

 lu' .l..no without till- h-JLst .hmjjiT, tlie poison hfinji (juite innocuous when t;iken internally— cnt- 

 li«H ..ut tlic wounded i>art, <.r hurninjr it witli a hot iron or witli caustic applications. All tliesc 

 rcmdics must, howcwr, W adoptcl innncdiatcly after the wound has heen received; if any time 

 be allowcl to elai>se the most distrcssiiiir symptoms make their appearance, and if these can be 

 roIii>vo«l I'V tlio administration of medicines, which, however, appiars somewhat doubtful, the 

 patient j,'enerally suth-rs f.>r a lon;^ period tVom the cft'ects of the bite. 



Thi- N'iperina' are divided into two families, the Crotalidcc, of which the rattlesnakes are the 

 typos, and the ]'lp<rlJ<r, of which tiie vipers arc the types. 



TUB liATTLESNAKE. 



THE CROTALID^ 



This family not only contains the rattlesnakes, but a considerable number of other species 

 distributed throuo-hout the warm parts of the earth; they are all particularly distinguished 

 by the presence of a deep pit on each side of the nose, situated beneath, and usually a little be- 

 hiiul the nostril. Tliis pit, the purpose of wdiich is still unknown, is lined with small plates. 

 The head is broad and flat, scaly on the crown, and furnished with small shields only on the 

 sides and nose. The teeth are very small, but the poison-fangs are exceedingly large and power- 

 ful ; an<l these snakes must be regarded as among the most dangerous of the ordei-. The belly 

 is covered with broad shields. 



Genus CROTALUS : Crotalus. — This includes the Rattlesnakes, of which there are several 

 species, all belonging to the continent of America. The Common or Northern Rattlesnake of 

 the United States, often called Banded Rattlesnake, C. durissus, is of a yellowish or reddish 

 brown, sometimes of a chestnut black, with irregular, rhomboidal, black blotches ; head large, 

 flattened, and trianguhxr ; neck small ; tail short ; length from three to four feet, sometimes 

 even as much as seven or eight. Like the other Viperina they produce their young alive. 

 Upon the tail is wdiat is called a rattle, consisting of several horny enlargements loosely attached 



to each other, and making a loud rattling 

 noise when shaken and rubbed against 



KATTLE Of TWENTY-FOUR JOINTS. 



each other. These rattles generally in- 

 crease with the age, but not regularly 

 once a year, as is supposed. Two and 



even four have been known to come in a year, and sometimes several of the rattles drop oft"; 



they are seldom over twenty-five in number. The use of these extraordinary appendages seems 



