INTRODUCTION. XXI 



number of perfect and moveable ribs, by an entire covering 

 of scales, which in most families are imbricated, in others 

 flat and with their margins in mutual contact. The eyes 

 are furnished with eyelids ; the ear in some protected by a 

 simple valve, in others by scales rather larger than the 

 surrounding ones, and in others the tympanum is on a level 

 with the surface of the skin. 



In this group are found some of the most active, and 

 certainly the most beautiful of the reptile class. Many of 

 them are tinctured with the most brilliant colours ; and as 

 they are called into the greatest activity in the bright sun- 

 shine, nothing can surpass the splendour of their ever- 

 changing hues. Most of the Saurians are insectivorous ; 

 but there are some, as the Iguanas, which live principally 

 on fruit. The activity of the smaller insectivorous Lizards, 

 when in pursuit of their food, is exceedingly curious and 

 interesting. They watch with all the caution of a cat, and 

 dart upon their prey with the quickness of lightning. 



In the act of seizing their food, however, they must 

 necessarily be exposed to some danger from the noxious 

 qualities of the insects which they indiscriminately attack. 

 The following fact would seem to indicate that even in our 

 own temperate climate, an insect not generally recognized 

 as poisonous may inflict a fatal injury upon its Saurian 

 enemy : — Some years since, I had in my possession two 

 living specimens of the beautiful little green anolis of the 

 West Indies, a Lizard about the size of our own smallest 

 species. I was in the habit of feeding them with flies and 

 other insects, and having one day placed in the cage with 

 them a very large garden spider, Epeira Diadema, one of 

 the Lizards darted at it, but seized it only by the leg. 

 The spider instantly ran round and round the creature's 

 mouth, weaving a very thick web around both jaws, and 



