BROOKESIA AND RHAMPHOLEON 



tailed monkeys of the New World and to the tailless or 

 stumpy tailed forms among the monkeys of the Old 

 World. But in the case of the chamaeleons all are Old 

 World. Male and female chamaeleons often show exter- 

 nal differences, some of which are quaint and exagger- 

 ated. The common chamaeleon, which is African, and 

 just extends into Europe and Asia Minor, shows the 

 slightest difference of this kind ; in the male, the casque, 

 as we may term the posterior projecting end of the head, 

 is longer than in the female. Several species, appropri- 

 ately named " Calcarifer " and " Calcaratus " on this 

 very account, have a kind of spur on the hind legs just 

 above the ankle, which spurs are again peculiar to the 

 males. But the most extraordinary difference of the 

 kind is to be seen in a few forms, of which a species found 

 high up at an altitude of 6,000 feet on Mount Ruwenzori, 

 in tropical Africa, forms an example. This chamaeleon, 

 which was named after Sir Harry Johnston, presents us 

 with three long horns upon the forehead, which give to 

 this reptile a most truculent aspect. Another species 

 from the same mountain has in front of the nose a for- 

 wardly directed bony outgrowth. No chamaeleons are 

 very large. Brookesia and Rhampholeon, just alluded 

 to, are quite tiny, three inches or so. So, too, is the 

 ",dwarf chamaeleon," a South African species, charac- 

 terized by its green colour and by a patch on the side of 

 a beautiful brick red. On the other hand, the giant of 

 the tribe, Chameleon parsoni, is a couple of feet or so in 

 length. 



THE MONITOR OF THE NILE 



Varanus niloticus is the full-dress name of a large 

 lizard whose habitat is indicated by it s name, but which 

 also strays into other parts of Africa. It is one of a 

 genus of lizards entirely confined to the Old World, which 

 has been variously termed Monitor, Varanus, Regenia, 



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