98 THE SNAKES OF SOUTH AFRICA. 
species of snakes. This constant creation of new species in 
Zoology is being carried to an extreme and will doubtless create 
endless confusion and labour in the future, if continued. In 
the case in point the difference is merely a matter of variation 
which is by no means constant. Naturally, if a large series 
should be examined, and if the difference should be seen to be 
constant, then there is justification for the creation of a new 
species, not otherwise. 
The generic name Simocephalus has been previously used for a 
genus of Crustaceans, and will require to be altered. 
THE MOLE SNAKE. 
ALSO KNOWN AS THE ZWART SLANG, LUI SLANG, MOL SLANG. 
(Pseudaspis cana.) 
The Mole Snake is widely distributed over South Africa. 
It varies considerably in colour. Some specimens are shiny black, 
others brick red, or brown spotted with black. The Mole Snakes 
‘ and House Snakes can be regarded as typical examples of non- 
venomous snakes, Young Mole Snakes are brown, with irregu- 
lar black markings. Many of these about two feet long are light- 
brown with wavy black markings on the back, and are also spotted 
and blotched with white. Adults are usually found most 
abundantly about the haunts of moles, mole-rats, field-rats and 
vlei otomys, in sandy soil, sparsely covered with scrubby bush. 
The young haunt stony hillocks, and rough, rock-strewn ground, 
in pursuit of lizards, on which they mostly feed. In captivity, 
Mole Snakes usually refuse all food. Occasionally I have induced 
them to eat, and have observed them constrict and swallow moles 
and rats. 
Mole Snakes, when surprised, will show fight, boldly facing 
the intruder and making desperate lunges in his direction, with 
gaping mouth and slightly raised body. This habit of raising 
the fore part of the body and head, and general outward similarity 
to the Cape Cobra, causes them to be mistaken usually for the 
latter. Apart from the difference in the formation of the teeth 
and scales, Mole Snakes can easily be distinguished from cobras. 
Their heads are narrow, and join the body without any narrowing 
at the neck region. Their bodies are nicely rounded (cylindrical), 
