32 



LlZAKDS.- 



-REPTILES. 



-TmCK-TONGUKD I^IZAHUS. 



spines. . It is of a depressed form ; the head is small 

 and furnished with two or three very large spines over 

 the eyebrows. "/fhe external appearance of this 

 lizard," says Dr. Gray, who first made it known, " is 

 the most ferocious ot-auy that I know, the horns of the 

 head and themimeions spines on the body giving it a 

 most formidable aspect." " I have named this genus," 

 .5he adds,-"irura- its appearance, after 'Moloch, horrid 

 king.' " J^heseanimalsare highly coloured, especially 

 on the underiawl'aces, wliich are covered with black- 

 edged dari red spots. We do not know their habits, 

 but they «re harmless enough: 



Tribe III.— DENDKOSAURA- 



The third^trfbe of Thic^tongugd Lizards, and the 

 last of the Silurian 5eptiles,^slhat of the Tree Lizards 

 (Dendrosaura).* In this tribcth&rscales of the belly, 

 sides, and back are granular merely, and disposed in 

 circular bands. The toes are five in number on each 

 foot, and disposed in two groups, which are opposed to 

 each other, and admirably adapted for grasping the 

 branches of trees, &c. 



This tribe contains only one family, that of the 

 CiUMELEO.NS {ChameleonidcB) ; and this family consists 

 of only one genus {Chameleo),-\ and eighteen species. 

 They are all natives of the Old World, being confined 

 to Africa and Asia, though one of them has become 

 naturalized in Southern Europe. 



The Chameleons are truly singular animals, whether 

 we regard their internal or their external structure. 

 They ditfer so much from all other Saurians, that 

 Dumeril and Bibron place tlie family in a section 

 by themselves between the crocodiles and lizards. 

 " These animals," say these authors, " have such a 

 bizarre structure, and so different from that of all 

 other reptiles, that it is almost necessary to separate 

 them from the rest of the Saurians. It is with difficulty 

 we can observe even the slightest analogy between any 

 6[)ecies of Chameleon and any other lizard, whether 

 we look at the granular and variable disposition of the 

 integuments, or at the arrangement of the different 

 portions of the skeleton. In fact, none of them have 

 the slightest relation, either in the form and move- 

 ments of the tongue, or in the structure and mode of 

 articulation of the limbs, or, lastly, in the conforma- 

 tion and uses of the tail." In Dr. Gray's arrange- 

 ment, however, they close tlie series of the Lizards, 

 and this seems to be their true position. The essential 

 characters which separate the Chameleons from all the 

 ctlier families of the Saurians are three :— 1st. The 

 existence of a cyclindrical, worm-like, very long tongue, 

 which is terminated by a smooth, fleshy tubercle, lubri- 

 cated by a viscid s;iliva. 2nd. Their having their five 

 toes, in each foot, connected together as far as their 

 last joint, but divided into two unequal sets, three in 

 one and two m the other. 3rd. Their body being 

 compressed, covered with a shagreened skin, and their 

 tail being conical and prehensile. 



* From the two Greek words, deiulron (3i»S{».), a tree, and 

 aaura (ato'^oi^, a lizard. 



t From the Greek word chamailcon (x'^.fLxiXim), a little 

 lioii. 



The integuments of the Chameleons are destitute of 

 true scales; the skin is rugose, tubercular, and finely 

 shagreened by unequal projecting granules, which are 

 distributed in symmetrical groups. It appears very 

 loose, adhering seemingly to the muscles only on the 

 head, back, the free extremity of the tail, and the feet. 

 Besides this, throughout its w-hole extent, numerous 

 vacancies or free spaces are left, into which the air 

 froqj the lungs can penetrate, so as to inflate it. In 

 this skin there exist two layers — 1st. A mucous tissue 

 variously coloured by a pigment which appears to be 

 gifted with a peculiar chromatic property; and 2iid. 

 A true transparent epidermis which forms a continued 

 layer, and moulds itself most exactly upon all the 

 inequalities of the surface. The body is compressed or 

 flattened sidewise, from right to left, and surmounted 

 on the back by a projecting sharp ridge, a similar one 

 being seen also in some species along the belly. Their 

 legs are slender, elevated, and much longer in propor- 

 tion than those of any other reptile, so that they can 

 raise the body so high, that their belly never rests upon 

 the surfaces upon which they walk or climb. The 

 tail is rather long, of a conical shape, and like that 

 organ in some of the monkey tiibe is prehensile ; that 

 is, capable of twisting itself round, and grasping the 

 various substances upon which they move. The struc- 

 ture of this organ and that of their feet renders those 

 animals truly arboreal in their habits. The toes, as 

 we have mentioned above, are divided into two sets, 

 three on one side and two on the other, aiid these are 

 disposed inversely; that is, the set containing two toes 

 is placed externally on the fore feet, and the set con- 

 taining three is placed externally on the hind feet. 

 These two parcels of toes are opposed to each other, 

 and thus form regular pincers, by means of which they 

 can firmly grasp and retain hold of the branches of trees, 

 upon which they live. The head of the Chameleons is 

 very large and generally more or less strong!}' ridged, 

 and the neck is so short that the head appears to rest 

 upon the shoulders. There is no external ear apparent, 

 these organs being hidden under the skin. The orbits 

 are very largo, and the eyes are particularly prominent, 

 the globe being in a great measure situated outside 

 the cavity. The whole of this organ is covered with a 

 single eyelid, which is a contimiity of the skin of the 

 head, and is pierced with a small dilatable hole in the 

 centre, forming, in fact, a true external pupil, which 

 the animal can dilate or close at will. It can even 

 vary the shape of the opening, for we see it sometimes 

 become transverse or vertical. From the peculiar 

 arrangement of the nerves and muscles, each of the 

 eyes can move independent of the other. They can 

 move in different directions, one upwards, the other 

 downwards ; the one forwards, the other backwards ; 

 and in aU sorts of ways, without the head undergoing 

 any change of position. " You cannot tell," says Mr. 

 Gosse, " whether the creature is looking at you or not ; 

 he seems to be taking what may be called a general 

 vieio of things ; looking at nothing particular, or 

 rather, to save time, looking at several things at once. 

 Perhaps both eyes are gazing tqiwards at your face ; a 

 leaf quivers behind his head, and in a moment one eye 

 turns round towards the object, while the other retains 



