VIPERINE GROUP. 243 



the whole, while admitting that fear has probably some share in the matter, it 

 seems better to suspend our judgment before definitely committing ourselves to 

 any one particular view. That rattle-snakes are some of the most deadly of all 

 venomous serpents may be freely admitted ; and it seems that we must almost 

 concede that they possess the mysterious power of " fascinating " their victims 

 before striking. Moreover, the assertions as to the power possessed by vipers of 

 swallowing their young are equally numerous and well-authenticated in the case of 

 the serpents under consideration. 



The formidable South American snake (Lachesis muta} known 

 ' to the Dutch settlers of Guiana as the bushm aster, but by the 

 Brazilians termed the surukuku, differs from the rattle-snakes by the presence 

 of a distinct keel-like ridge down the back, and, in place of a rattle, having the 

 under surface of the tip of the tail covered with from ten to twelve transverse 

 rows of small, spiny, sharp scales, while the extremity terminates in a spine. 

 This snake attains a length of from 9 to 12 feet, and has the ground-colour of the 

 upper-parts reddish yellow, upon which is a longitudinal row of large blackish 

 brown lozenges, each having two light spots on either side of the middle line ; while 

 the under-parts are yellowish white, with a porcellarious glaze. The large size and 

 enormous poison-fangs of the bushmaster render it one of .the most formidable 

 of the pit- vipers ; its bite being apparently fatal to human beings in a few hours. 

 Fortunately it is far from common, and inhabits only the secluded portions of the 

 primeval forest, where it lies coiled up on the ground. Unlike most snakes, when 

 disturbed it makes no attempt to flee, but strikes with the rapidity of lightning at 

 the disturber of its slumbers. 



These snakes have the upper surface of most, or all, of the front 

 Halys Vipers. 



of the head covered with large shields ; the body is rather long 



and clothed with from seventeen to twenty-seven rows of keeled scales; and 

 the very short tail has its lower shields arranged in either a double or single series, 

 some species having a small spine at the extremity, which is regarded as a 

 rudimentary rattle. The genus is common to Asia and North and Central 

 America ; some half-score of species being known, two of which are found in India. 

 One species ranges as far east as the Urals, where it just enters the confines of 

 Europe. In habits they are all terrestrial. 



Himalayan Of the Indian species, in both of which at least the majority of 



Halys. the shields on the lower surface of the tail are arranged in two rows, 

 the Himalayan halys (Ancistrodon himalayanus) is distinguished by having two 

 pairs of large shields on the muzzle, the extremity of which is but little turned 

 upwards. In colour it is brown, with black spots or transverse bands, while some- 

 times a light festooned stripe runs down the back ; from the eye to the angle of 

 the mouth runs a black streak edged with white ; and the under-parts are either 

 dark brown, or Variegated with black and white. This snake, which grows to 

 nearly a yard in length, is abundant in the North- Western Himalaya, at elevations 

 of between five thousand and eight thousand feet, although it sometimes ascends 

 considerably higher. The carawila (A. hypnale), of Ceylon and Western India, is 

 a much smaller species, not exceeding 20 inches in length, and characterised by the 

 extremity of the upturned muzzle being covered with small scales. 



