the Caribaan Islands. 165 



being, from its structure, of necessity always compressed, even when ex- 

 tended, and never buUate and inflated as it might seem on a lateral view 

 of the animal. 



This circumstance I long since mentioned in a paper read before the 

 Royal Society, but as Mr. Bell has since said all that is necessary on the 

 subject, in his admirable observations on the structure of the throat in the 

 genus Anolis, inserted in the fifth number of the Zoological Journal ; and 

 has accompanied his anatomical details by a satisfactory plate, shewing 

 the remarkable developement of the os hyoides by which the palear is 

 extended; I shall for the present only observe, that the supposition 

 of Mr. Bell is quite correct, the skin of the sides being perfectly 

 united. It is of a light and striking color, which is probably useful in 

 attracting the female.* While in search of prey, the Anolides most com- 

 mon here always adapt (by some mysterious power) their color to the 

 green tree, or the dark brown rock, on which they lie in ambush ; and 

 were it not for this organ, which they can retract at pleasure, the male 

 might lie concealed when at a distance from the other sex, which it is 

 not able to entice by sounds. The process is stiffly extended, and, to 

 make it more apparent, the head and neck are moved up and down with 

 a violent jerking motion, dum mas feminam in nuptias solicitat. In the 

 cognate genus Ascalabotes, Cuv., which preys by night, this structure is 

 wanting. 



It may be advisable to repeat the description which was added at the 

 same time of the living Guana, as none but dead specimens appear to 

 have been studied by Zoologists in Europe. 



Reptilia. 



Ordo. Sauria. 



Divisio. Tereti-caudata. 



Fam. IguaniDjE, Befl, Guild. 



Genus. Lacerta, Linn. Iguana, Cuv., &c. 



Char, genericus. 



Corpus magnum, crassum, caudaque elongata, ordinibus parallelis squa- 



* Perhaps, like the Caruncula of the Galllnae, the organ may be principally 

 ornamental. 



