THE HTL^OSAUHUS. 
watcla, as motionless and still as tlie leaves tlieraselves ; and it is even difficult for any eye but 
that of the practiced angler to discover what shadowy form it is that ripples the whimpled water 
as the bold old trout sails leisurely up the stream, with his back-fin just peeping above the sur- 
face, on the loot-out for a May-fly for his luxurious repast." 
The Common- Chameleon of Europe, C. Africanus — CameUon of the French — is sixteen to 
eighteen inches long, the tail being nearly as long as the body. It occurs in all the northern 
parts of Africa, and also in India ; it has become naturalized in some parts of the south of Europe. 
Other species are as follows: the Rhustoceros Chameleon, C. rhinoceratus^ io\m<l in Mada- 
gascar: the Flap-necked Chameleon, C. dilejyis, found in Senegal and the vicinity : the Pearled 
Chameleon, C. pumihxs, found at the Cape of Good Hope: the Three-horned Chameleon, C. 
Owemi, found in Fernando Po. Most of the other species belong to Africa. 
Fossil Lizards. — In former parts of this work we have mentioned some of the gigantic fossil 
lizards whose vestiges have been discovered by the geologists. Among these we have described 
the Iguanodon (page 8, vol. I.), supposed in its structure and habits to have borne some resemblance 
to the existing iguanas, which we have described. But a few more particulars may be proper 
in connection with the order to which this extraordinary animal belonged. 
For our knowledge of this Monster of the Past, we are chiefly indebted to the energy, patience, 
and acuteness of Dr. Mantell, of London. Parts of several skeletons have been obtained, but 
none of them entire ; one, however, is so far complete as to make it certain that this species was 
of the most gigantic dimensions, some supposing it to have been a hundred feet in length. In 
the latest edition of Dr. Mantell's " Wonders of Geology," he speaks on this subject aslbllows : 
" The k-ngth of the Iguanodon has been variously estimated, the difference in the computation 
depending chiefly on the extent assigned to the tail, which in tlie Iguana and many other lizards 
is much longer than the body. If the tail of the fossil reptile was slender, and of the same rela- 
tive proportions as in the Iguana, the longest individual would be fifty or sixty feet long ; but it 
is more probable, from the shortness of the bodies of the caudal vertebrae, .that the tail was com- 
paratively short and flattened at the sides, as in some living reptiles, for example, the DoryphoruH. 
In that case the length of a full-grown Iguanodon would but little exceed thirty feet."* 
* Mr. TV. Hawkins has prepared restorations of many of the gigantic fossil animals, representing them as they are 
supposed to have appeared, and these are exhibited at the Crystal Balaee, Sj-denham, near London. In this he 
was assisted by Dr. Owen, who ranks as the first living Comparative Anatomist." Dr. Mantell regarded those restora- 
tions as executed with great skill and science, and worthy of every confidence. Several of them we have copied 
here and elsewhere in the present work. 
