THE VIPERS 2611 



prehensile tails and the arrangement of the scale.8 on the body in from thirteen to 

 twenty-three rows; the figured species usually having twenty-one rows of scales, 

 while there are from seven to thirteen scales in a transverse series on the head 

 between the supraoculars; the temporal scales are smooth, and the shields on the 

 lower surface of the tail vary in number from fifty-three to seventy-five. Attaining 

 a length of two and one-half feet, this snake usually has the upper parts bright 

 green, although in some specimens they may be yellowish, grayish, or purplish 

 brown, while they may or may not be marked with black, brown, or reddish spots. 

 Generally there is a light colored or reddish streak along the outer row of scales, 

 and the end of the tail is frequently red or yellow, the under parts being green, 

 yellow, or whitish. Ranging from Bengal to the Malayan region, this species is 

 thoroughly arboreal in its habits. Stoliczka states that he found these snakes very 

 common about the limestone hills near Moulmein, where they are exactly of the 

 same green color as the foliage among which they hide themselves. He saw small 

 specimens very often on low umbelliferous plants growing about a couple of feet 

 high. One of the snakes had its tail wound below around the stem of the flower on 

 the top of which it was basking. All were very sluggish and did not make the 

 slightest attempt to escape when approached, and even allowed themselves to be 

 removed from the top of the plant. Neither did they offer to bite, unless when 

 pressed to the ground with a stick; but when thoroughly aroused, they turned 

 round and bit furiously. The rat-tailed pit viper or fer-de-lance ( T. lanceolatus) is 

 one of several American species with nonprehensile pointed tails, whose habits are 

 terrestrial. Reaching a length of nearly seven feet, with a body as thick as a 

 man's arm, this snake is very variable in coloration, the ground color of the upper 

 parts being generally a reddish yellow brown. The distinctive markings take the 

 form of a black stripe, which is but seldom absent, running from the eye to the 

 neck, and of two rows of irregular dark cross bands on the body. In some speci- 

 mens the sides of the body are, however, of a bright red. The form and arrange- 

 ment of the scales on the head, the presence of seven upper labial shields, and the 

 arrangement of the body scales in not more than twenty-nine rows, together with 

 the uniformly-colored under surface of the body, serve to distinguish the species 

 from its congeners. This snake is an inhabitant of the Antilles and Central 

 America. During the daytime it lies curled up in repose within the middle of the 

 coils of the body, ready to dart out with the rapidity of lightning on the approach 

 of an enemy. 



The mainland of South America is the home of the two closely-allied 



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terrestrial representatives of the genus, respectively known as the 

 jararaca ( T. jararaca) and the labaria ( T. afrox}, which are exceedingly difficult to 

 distinguish from one another. The former, which ranges from Amazonia south- 

 ward to San Paulo and westward to Ecuador and Peru, has eight or nine upper 

 labial shields on the snout, and from twenty-five to twenty-seven rows of scales on 

 the body; the general color of the upper parts being gray or grayish brown, with 

 small dark brown cross bands, bordered by darker edges, while the under parts are 

 gray, with two or four irregular longitudinal rows of whitish or yellowish spots. 

 The labaria differs in having only seven upper labials, as well as in certain details 



