268 TROPICAL MEDICINE AND HYGIENE 



brown to blackish, the skin between the scales being 

 black. Its venom is estimated to be even more potent 

 than that of the Indian Krait (Bnngarus candidus), and 

 is said not only to be strongly neurotoxic as well as 

 to have powerful effects on the blood (coagulant and 

 haemolytic according to dose), but also to have a direct 

 effect upon the heart. 



(d) Pseudechis. This genus is distinguished from 

 Notechis and Denisonia by the two rows of subcaudal 

 shields (at least in the posterior part of the tail), and from 

 Diemenia by having the maxillary teeth behind the poison- 

 fangs fewer in number and not grooved. There are eight 

 species, one of which, known as the " Black Snake" 

 secretes a venom that is said to be most markedly 

 haemolytic besides being neurotoxic. 



(e) Acanthophis includes only one species, Acanthophis 

 antarcticus, the " Death-adder." It strongly resembles a 

 viper, having a broad head, a narrow neck, a stodgy body, 

 and a short tail. The tail ends in a sort of horny spike. 

 The eye is separated from the labial shields by sub-oculars, 

 and sometimes the supra-ocular shield is raised and horn- 

 like. The venom is estimated to be more virulent than 

 that of the Indian cobra, and is neurotoxic, haemolytic, 

 and also a vasomotor depressant. 



Postcript on Habits of Snakes. This matter can only be 

 treated very briefly from the " preventive " point of view. 



As a rule, to which, of course, there are plenty of 

 exceptions, the snakes that are most likely to be found 

 in and about human habitations are Elapines. The 

 Viperidae include so many desert-lovers and denizens 

 of the bush and jungle, not a few of them actually 

 showing adaptive modifications to their habitat, that they 

 are not so liable to come in contact with man, except 

 in camp and in tents. Of course there are also some 

 Elapines that are adapted to a particular habitat. 



The snakes that are commonly found in dwellings and 

 outhouses in the Tropics, especially where there are 

 thatched roofs, are things like Cobras and Kraits, which 



