66 Zoological Society. 



find but few edible roots among rocks, but very thinly interspersed 

 with soil. In the occasional hollows a little mould has been col- 

 lected from decayed leaves, mingled with marl, extremely stony and 

 sterile ; and here a little more succulent herbage may prevail, and a 

 few of the edible roots of the country may be found growing. The 

 rocks have numerous caverns, and the springs that break out at the 

 foot of the cliffs are an impure brackish water, though extremely 

 transparent. Yet this district is almost exclusively the haunt of 

 the Iguana. The occasional ones taken in the savannas are con- 

 sidered to be stray visitants from the neighbouring hills ; they are 

 not permanently established in the plains in which they are found. 



" I have noticed the particular kind of locality which the Iguana 

 inhabits in this part of the country, because it presents very different 

 features from the haunts usually assigned to this lizard elsewhere. 

 Forests on the banks of rivers, and woods around springs, where it 

 passes its time in the trees and in the water, living on fruits, grains 

 and leaves, are said to be the places in which the hunters find it on 

 the American continent " 



After referring to some notes of Sir R. Schomburgk made in 

 Guiana, and to Goldsmith's graphic picture of noosing the Iguana, 

 probably derived from Labat, which I do not here quote, because 

 they refer to an animal generically distinct from ours, — my friend 

 reverts to his own observations : — 



" The gular pouch which hangs like the dewlap of a bull beneath 

 its throat can be inflated*, but it is not exactly known under 

 what circumstances, ordinarily, it has recourse to this power of in- 

 flation. When filled with air it would give breadth and buoyancy 

 to the body, and if its habits are as aquatic as some accounts make 

 them [those of Iguana proper] to be, it would afford to an her- 

 bivorous animal no unimportant aid while swimming and cropping 

 • its flowery food.' When excited it assumes a menacing attitude, 

 and directs its ej'^e to the object of attack with a peculiarly sinister 

 look. At this time it inflates the throat, erects the crest and dente- 

 lations on the back, and opens the mouth, showing the line of those 

 peculiarly-set white teeth, with serrated edges, so excellently made 

 to illustrate the remains of the gigantic fossil Iguanodon, The prin- 

 ciple of their construction is so precisely similar, as to leave no doubt 

 of the genuine connexion of the extinct with the existing herbivorous 

 lizard. The adaptation of both is for the cropping and cutting of 

 vegetable food. 



" In defending itself from attack, the Iguana converts its long 

 flexible tail into no unimportant weapon. The dentelated upper 

 edge, drawn rapidly over the body and limbs of an enemy, cuts like 

 a saw. The twisted attitude which it assumes when approached is 

 converted into a quick turn, in which movement the tail is nimbly 

 struck by an overblow from one side to another, and then jerked 



* I believe my friend has fallen into a common error here. If I may judge 

 from analogy in the genera Anolis and Dactyloa, the gular pouch in the Iguanidce 

 is extensible but not inflatable, as I hope to show in a future paper on the habits 

 of these genera. — P.H.G. 



