SAURIA. 35 



other back of the jaws, which are lost on the shoulder.(l) It 

 is from Guiana, and feeds on grain. 



POLYCHRUS, CuV. 



Teeth in the palate as in Iguana, and femoral pores, though the 

 latter are not strongly marked; but the body is covered with small 

 scales, and is destitute of a crest. The head is covered with plates; 

 tail long and slender; throat very extensible, so that a dewlap is 

 formed at the will of the animal, which, like the Chameleon, possesses 

 the faculty of changing colour; the lungs, consequently, are very vo- 

 luminous, occupy nearly the whole trunk, and are divided into seve- 

 ral branches; the false ribs, like those of the chameleon, surround the 

 abdomen by uniting so as to form perfect circles. 



Lac. marmorata, L.; MarbrS de la Guiane, Lacep. I, xxvi; 

 Seb. II, Ixxvi, 4; Spix, XIV. Reddish-grey, marbled with irre- 

 gular transverse bands of a brown-red, sometimes mixed with 

 blue; the tail very long. Common in Guiana.(2) 



EcPHiMOTus, Fitzinger. 



Teeth and pores of a Polychrus, but small scales on the body only; 



on the tail, which is very thick, they are large, pointed, and carinate; 



the head is covered with plates. Their form is somewhat short, and 



flattened, more like that of certain Agamse than of a Polychrus. 



The most common species, Agama tuberculata, Spix, XV, 1, 

 or Tropidurus torquatus, Pr. Max. (3) is ash-coloured, sprinkled 

 with whitish drops, and has a black semi-collar on each side of 

 the neck. It inhabits Brazil. 



Oplurus, Cuv.(4) 



Teeth of a Polychrus and the form of an Agama, but no pores on 

 the thighs, and the pointed and carinated scales of the tail ally it to 

 that of a Stellio; the dorsal scales also are pointed and carinate, but 

 very small. One species only is known. 



(1) It is on the authority of Seba that this species has hitherto been considered 

 as hihabiting India — it does not inhabit that country. 



(2) Add, Pol. acutirostres, Spix, XIV. 



(3) The Tropidurus of Pr. Max. de Wied. is not, as he imagined, the Quetzpaleo 

 of Seba, although it is also marked with black semi-collars. 



(4) The name of Quetzpaleo, given by Seba to the above species, seems to be a 

 corruption of the Mexican Jgua quetz pallia, which appears to be a name of the 

 Iguana; the Quetzpaleo of Lacep., Rept. 4to, II, 497, is a Uromastix; but the figure 

 quoted is that of Seba's animal. 



