COLOURATION OF REPTILES AND AMrillBIANS. 265 



Zonurus polyzomts adheres so strictly to the same environment 

 that it has no need for such a property. The common skink, 

 Mabiiia trivittata, which can change from quite a sombre colour 

 to a light reddish brown according to the colour of the surround- 

 ings, produces ten young at a time. It would appear that 

 Zonurus can have few enemies that really count outside snakes, 

 and these, at least in the Kimberley neighbourhood, are not plenti- 

 ful. In any case, the habit of sitting on a rock just over the 

 narrow cleft which forms their retreat gives them a chance of 

 disappearing at the first sign of danger. If the snake were small 

 enough to enter the cleft it could seize only the tail, which is 

 turned over to shield the body, and this v^^ould break off, leaving 

 the lizard unharmed. Birds of prey seldom or nev^er see the 

 bright-coloured ventral side, and the dark, almost black, dorsal 

 colour renders them invisible against tlie similarly coloured rock 

 when viewed from above. 



Again, some hawks used to roost on a building in Kimberley 

 at one time, and in searching their droppings I found the remains 

 of several Againas and skinks; no fragment of a Zonurus was 

 found, yet I have no reason for suspecting that Zonurus is dis- 

 tasteful to birds of prey. 



Whilst the dorsal colouration of these rock-dwelling or ter- 

 restrial kinds is almost always protective, that of the arboreal 

 Agamas is apparently not so : it seems to belong to the type 

 known as 



Alluring or Pseudepisematic Colox^ration. 



When the colours of an animal imitate those of some other object 

 in order to attract its prey, it exhibits what was termed " alluring 

 colouration " by the late Mr. Wallace, " pseudepisematic colours " 

 by Prof. Poulton. 



About November, 1906, tlie butterfly Callidryas florella ^vas 

 very plentiful on the veld near Kimberley. and large numbers of 

 them were to be seen hovering over the tops of the grass and 

 bushes. I noticed that under certain bushes numbers of wings 

 and portions of wings of the above-mentioned butterfly were col- 

 lected. I did not at the time realize the full meaning of this 

 and did not identify the responsible foe, but I now strongly sus- 

 pect that it must have been Agania aciilcata, although it may have 

 been a bird. 



However, six years later I was fortunate enough to make 

 the following interesting observation. One sunny afternoon in 

 November, 191 2, I was admiring a fine male A. aculeata display- 

 ing his beautiful head and chest on a thorn-bush. Perched there 

 motionless, he looked like an attractive flower with the outer 

 petals of brick red, the inner ones a blue cluster in the centre. As 

 I gazed admiringly at him a butterfly, to my utter amazement, 

 deliberately landed on the tip of his snout, and before I could 

 realize what was happening he had swallowed the insect, discard- 

 ing the wings — probably because they are such dusty and un- 

 satisfactory things to eat. 



