Southeast Asia 



Distribution: Southern India and Ceylon. Inhabits 

 dense jungle and coffee plantations in hilly country. 



Remarks: Often found by day coiled in bushes. It 

 is irritable and vibrates the tail when annoyed. Bites 

 by this snake are seen fairly frequently, but serious 

 poisoning has not been reported. There is no antivenin. 



ASIAN LANCE-HEADED VIPERS 

 (Jrimeresurus) 



This large genus, containing some 30 species, is 

 closely related to tropical American lanceheads 

 {Rothropx). All have large triangular heads 

 much wider than the neck. Presence of the facial 

 pit and absence of large ])lrttes* on the to]) of 

 the head (fig. OG) distinguish them from most 

 other snakes within their range. The pupils of 

 the eye are elliptical; the subcaudals may be 

 divided or undivided. 



Bites by tliese snakes are quite frequent ; how- 

 ever, the fatality rate is very low. The American 

 polyvalent Crotalid Antivenin (AVyeth, Inc.. 

 Philadelphia) shows neutralizing activity against 

 A-enoms of several Asian lanceheads. It should 

 be used if specific antivenin is not available. 



CROTALIDAE: Genus Trimeresurus Lac6pede, 1804. 

 Asian lance-headed vipers. 



About 30 species are currently recognized. All are 

 found in southeast Asia and the adjacent island chains. 

 The large spe<'ies are dangerous ; many of the smaller 

 kinds can deliver a venomous bite which is very painful, 

 but seldom if ever fatal (see pp. 137-138 for description 

 of other species that enter this region). 



There are 3 general grou|is of these snakes : 



1. Large, long-bodied and long-tailed terrestrial snakes 

 that are often brightly-colored with contrasting pal- 

 terns ; 



2. Small short-bodied and short-tailed terrestrial 

 snakes, commonly with dull patterns of brown blotches; 



3. Small, moderately long-bodied arboreal snakes with 

 prehensile tail, body coloration tending toward \inicolor 

 greens, light browns, or light speckles. 



Drflnition: Head broad, flattened, very distinct from 

 narrow neck ; canthus obtuse to sharp. Body cylindrical 

 to moderately compressed, moderatel.v slender to stout : 

 tail short to moderately long. 



Eyes small to moderate in size ; pupils vertically el- 

 liptical. 



Head scales: Supraoculars present, a pair of inter- 

 nasals often present : remainder of crown covered with 

 small scales. Laterally, a nasal pore in prenasal. 2 en- 

 larged preoculars, eye separated from supralabials by 

 1—4 rows of small scales. 



Body scales : Dorsals feebly to strongly keeled, in 

 13-3T nonoblique rows. Ventrals 129-231; subcaudals 

 paired, 21-92. 



Chinese Green Tree Viper, Trimeresurus stejnegeri 

 Schmidt. 



Identification: One of a group of very similar ar- 

 boreal pit vipers found throughout much of tropical 

 Asia. All are slender to moderately stout snakes with 

 l)rehensile tails. In this species the first upper lip shield 

 is not fused with nasal shield and the dorsal scales are 

 keeled. 



Body bright green to chartreuse above, yellow to pale 

 green ventrally ; white or yellow line on side of body 

 edged with reddish in male ; upper lip yellow or green ; 

 iris of eye orange to coppery ; end of tail reddish 



Average length about 20 inches. 



* Present in T. macrolcpis of south India. 



FiouRE 92. — Chinese Green Tree Viper, Trimeresurus 

 Ktcjncprri. Photo by I.sabelle Hunt Conant. (See 

 also plate IV. figure 2.) 



Di.strihiilion: Central and southeastern China includ- 

 ing Taiwan. Occurs chiefly in mountainous country 

 near streams. Fre<iuents woodland, scrub and semi- 

 cultivated land. 



Pope's Tree Viper, Trimeresurus popeorum Smith. 



Iili ntijU-utiiiii: Separated from T. stejnrgcri pri- 

 marily by the structure of the male sexual organs; how- 

 ever, the following additional points of difference are 

 noteworthy : 



1. Iris yellow rather than reddish ; 



2. Size larger, reaching about 3 feet ; 



3. Lateral stripe indistinct in adult. 

 Distrihution: Assam and Burma east to Cambodia 



and south through Malaysia and Indonesia. Inhabits 

 hills between 3,000 and ."i.OOO feet for the most part. 

 Common on tea plantations. 



White-lipped Tree Viper, Tnmereswus alboldbris 

 (iiay. 



Identificatidii: First upper lip shield fused with nasal 

 shield; white lateral line in males only; upper lip pale 

 green, yellow or white; green of body generally some- 

 what paler than in T. stejnegeri ; iris of eye yellow; end 

 of tail dark red. 



Average length 15 to 2.5 inclies, maximum 36 inches; 

 females considerably larger than males. 



129 



