520 LACERTAE CHAP. 



in a very faded garment. His skin suggests a bright calico 

 after it has been washed, whose colours succumb to soap. The 

 blue is there, but it is no longer the bright blue of yesterday. 

 It has changed to a dull light indigo colour. He runs across 

 the grass to the foot of another tree, and stops on the bare 

 ground at its base, where for a minute or more he bites with 

 great energy at a struggling grasshopper, and while thus exercising 

 himself the blue fades out from his body altogether, and his 

 whole body takes the colour of the brown earth on which he 

 stands. After tarrying a minute or two he ran up the other tree, 

 and the dull light blue colour seemed to return to him." 



Agama with many species in Africa and Asia ; some in South- 

 Eastern Europe. The body is somewhat depressed. There is a 

 fold across the throat and a pit on either side ; the presence of a 

 gular sac is variable. A dorsal crest is absent or but feebly 

 developed. The males have pre-anal pores. 



A. sanguinolenta. The body is covered with strongly keeled 

 and pointed scales. On the sides of the head are a few spine-like 

 scales. The ear-opening is partly concealed by a fringe of spinous 

 scales. The males have a gular pouch. This is a typical 

 inhabitant of the deserts and steppes of Turkestan. Zander l has 

 observed the habits and many changes of colour of this lizard. 

 The usual garb is earthy brown above, with somewhat darker and 

 rather indistinct markings. The under parts are whitish. Some- 

 times the creature changes to dirty white, at other times into 

 blackish or grey brown. Bluish-red stripes may appear on the 

 sides of the body ; blue lines begin to show on the throat, and 

 ultimately the whole belly, originally white, may become ultra- 

 marine blue. When the general tone happens to be sulphurous 

 yellow, blue often appears on the tail and limbs. Brick red 

 appears on four longitudinal rows of patches on the sides of the 

 body. Sometimes the whole animal assumes a vinous tinge, or 

 it is at first greenish before turning into blue. The change 

 begins on the tail and limbs, extends over the head, and at 

 length reaches the back. Eed appears in both sexes, more 

 frequently in the female; blue almost entirely in the male. 

 Sunlight and warmth only intensify the colours. Adaptive 

 coloration, besides the usual sandy garb, has not been observed. 

 The lizards live on soil which is baked as hard as bricks, or in 

 1 Zool. Garten. 1895, p. 232. 



