98 SAURIA. IGUANAD^. 



somewhat of the form of a four-sided pyramid. 

 The neck is compressed, the body rounded, but 

 flattened on the under surface. The toes are 

 long, and very unequal, increasing rapidly in 

 length from the innermost to the fourth, which is 

 longest, the fifth being short: their edges are 

 notched. The tail is long, slender, compressed, 

 and tapered to a fine point. 



The general surface of the body is covered 



with small square or lozenge-form scales, 



keeled along the middle, which slightly overlap 



each other ; those of the tail present at regular 



intervals verticillations or rings, produced by 



every fourth or fifth series being a little larger 



than the others, but this structure ceases to be 



perceptible towards the tip. The line of scales 



which runs down the middle of the back and tail, 



forms a saw-like crest, commencing from the hind- 



• head, and reaching the extremity of the tail. It 



is composed of strongly compressed scales, which 



are pointed and curved backwards, and which 



gradually diminish in height towards the end of 



the tail. On the top and sides of the head the 



scales are larger than the rest, but varying in 



size, many-sided, some flat, some convex, and 1 



some ridged : the lips are covered with large 



four -sided plates. The under surface of the 



thighs has a single row of pores, surrounded by 



small scales disposed like the petals of a flower 



around its disk.* 



We have already mentioned MM. Dumeril and 

 Bibron's conclusions of the nature of ^ these Rep- 

 tiles' food from anatomical investigation. These 

 are confirmed by a fact related of a living Iguana, 



* Dum. et Bibr. 



