Liberia ^«- 



snakes by the Americo-Liberians) grow to between four and 

 five teet. 



A tract as pis is shorter (about three feet), and somewhat 

 thick in the body. It does not at first suggest relationship to 

 the vipers, as there is no well-marked " neck " or expansion of 

 the jaws to enhance the separation of head and throat. This 

 viper has only the poison fangs in the front of the upper 

 jaw, and no other teeth behind, but it still retains a separate 

 row of small teeth on the palate. It has a longer tail than 

 the true vipers, and, as already mentioned, lays eggs, and does 

 not brinw forth its young alive. 



CausiiS rhombeatiis is very common in I>iberia, just as it 

 is throughout Africa south of the Sahara. It is a small, 

 slender viper, with the head distinctly marked off from the 

 neck. The Causus viper is only about two feet in length, but 

 very venomous and dangerous from its insignificant appearance 

 and size. It is olive-brown in colour with V-shaped brown 

 marks along- the back, and a reversed V or arrow mark on 

 the top of the flat head. 



Atheris chlorechis is a tree-dwelling viper of no great size, 

 perhaps at most two feet in length. It is remarkable in the 

 first place for its long and prehensile tale. Very few vipers 

 are tree-haunting snakes, most of them being confined to the 

 ground in their habits, and in consequence the tail is never 

 very long, and does not seem to be prehensile. But in Atheris 

 both body and tail are long and lithe in comparison with what 

 characterises the true vipers. Moreover, Atheris in its bright 

 Screen colouring differs from the brown, yellow, grey, and 

 reddish black of the terrestrial vipers. The emerald-green of 

 this snake (in A. chlorechis) is dotted here and there with small 

 dark blue spots. The head is heart-shaped, and set on a rather 

 slender neck. The scales on the head and especially on the 



8o§ 



