Poisonous Snakes of British Guiana. 407 



speckled. In very young specimens the end of the tail is 

 yellowish white from birth and the general marking is much 

 deeper and richer than in the adults. 



Full-grown specimens reach a length of about 5 feet, the 

 females being much stouter in proportion than the males. 

 The number of young at a birth, from observed cases, appears 

 to range from twenty to thirty, as in the rattlesnake ; but the 

 young labarrias are much smaller in proportion, corresponding 

 to the markedly thinner build of the body in the two species. 



As already mentioned, this is the commonly distributed 

 forest- or bush-viper. Many harmless colubrine snakes and 

 some of the boas, which possess some resemblance to it in 

 markings, are frequently mistaken for it — mistakes that are 

 very likely to be confirmed in the mind of the observer by 

 the fact of the more or less severe pain and swelling which 

 temporarily follow the bite of many of the colubrines with 

 elongated and enlarged posterior teeth. One of these latter 

 (Helicops angulatus) goes by the common name of water- 

 labarria, and on this account bears an unjustly bad repu- 

 tation. 



The three vipers above described are strictly terrestrial 

 forms, but the green labarria (Lachesis bilineatus) is an 

 arboreal species with prehensile tail. The body is uniformly 

 green or spotted and speckled with black, and is marked on 

 the outer scales with a yellow lateral line or series of spots. 

 The end of the tail is red. 



This species, which reaches a length of from 3 to 4 feet, 

 does not appear to be common, or it well may be that it is not 

 frequently observed owing to its green colour; and there are 

 consequently but few cases of its being taken. Several 

 green and harmless colubrines, and even the green boa, are 

 generally mistaken for it, and they all appear to be designated 

 u parrot "-snakes on account of their colour. The finely- 

 scaled head with raised anterior edges, the loreal pit, the 

 viperine fangs, and the other crotaline characters, however, 

 will easily serve to distinguish it. 



The remaining venomous species all belong to the genus 

 Elaps, which is the American representative of that section of 

 the Colubiina to which the cobra and the greater number of 

 the Eastern venomous serpents belong. In them the anterior 

 maxillary teeth are perforated fangs which are permanently 

 erect, the jaw not hinging on the skull as in the viperine 

 snakes. 



As already stated, only one of these species, the largest 

 {Elaps surinamensis), is really to be dreaded; in the Colony 

 it goes by the common name " Himeralli," and attains a 



