LIZARDS 



57 1 



t'ntta uy If. Savillt-Kent, f.Z.S. 



AUSTRALIAN YORK OR MOUNTAIN -DEVIL 



A spinous lizard -which inhabitt the arid plains of Central Australia 



emerald- green and pale French grey. Around 



the lips and eyes there are lines of brightest 



yellow, and the throat is almost pure white. 

 The small group of GIRDLE-TAILED 



LIZARDS belongs exclusively to the African 



and Madagascan regions, its typical repre- 



sentative being the Cape and Orange River 



Colony species, illustrated on page 575. The 



symmetrical whorls of long, spinous scales 



encircling the tail in this and the allied 



forms constitute a prominent feature, and 



have originated the popular name of Girdle- 



tails. 



The most aberrant representatives of 



the Lizard Tribe, with regard to one very 



important characteristic, are undoubtedly the 



two species of HELODERM, or" SILATICA," as 



they are called by the natives. These reptiles 



(page 576) occupy the unenviable position of 



being the only known lizards which possess 



poisonous properties, their bite having been 



demonstrated to be fatal to smaller mammals, 



and to be attended by very serious symptoms in the case of human subjects being bitten. 



The more common MEXICAN HELODERM has been in residence at the Zoo for many years; it 



attains to a length of from 18 to 20 inches, and its stout, squat body, short limbs, warty skin, 



and peculiar colouring are calculated at first sight to awaken a feeling of revulsion in the 



beholder. Like the wasp, the salamander, and other animals whose conspicuous tints indicate 



their poisonousor other baneful properties, the heloderm is distinguished by a lurid ground- 



colour, varying in individuals from yellow-orange to flesh-pink, upon which are superimposed 



bold, network-like markings of blue-black or dark brown tints. Along the tail these reticu- 



lations usually take the form of more or less 

 irregular rings. 



Although the heloderms possess such 

 deadly properties, those at the Zoo manifest 

 a by no means aggressive disposition, and 

 allow their keeper or even strangers to handle 

 them with impunity. In experiments pur- 

 posely made to substantiate or refute the 

 previously current rumours as to the poison- 

 ous nature of these animals, two guinea-pigs 

 succumbed to bites received in the course 

 of the day. The owner of the reptiles, who 

 was also bitten on one occasion through 

 incautiously handling, suffered very severe, 

 though happily not fatal, effects. In con- 

 nection with its poison-dealing properties it 

 is found that it possesses certain long and 

 fang-like teeth, which are set loosely in the 

 jaws, and which have grooves before and 

 behind for the transmission of the poison, 

 which is secreted by special glands situated 

 close to their base. The favourite habitat of 



ph.i,h iv. 



, F.Z.S. 



SPINOUS LIZARD, OR MOUNTAIN-DEVIL 



TMs species feeds exclusively upon ant> 



