SAURIAXS. 29 



spines smaller; in other respects similar to the preceding. Both of 

 them have an oblique whitish line on the shoulder. The latter is 

 from the same country as the former, and is probably a mere variety 

 of age 6r sex*. 



Ig. nudicollis, Cuv. ; Mus, Besler. tab. XIII, f. 3; Ig. delicatis- 

 sima, Laur. (The naked Iguana), resembles the common one, parti- 

 cularly in its dorsal crest, but has no infra-tympanal plate, nor the 

 scattered tubercles on the sides of the neck. The upper part of the 

 cranium is furnished witli arched plates; the occiput is tuberculous; 

 the dewlap is moderate, and has but few indentations, and those only 

 in the anterior part. Laurenti says its habitat is India, but he is 

 mistaken ; we have received it from the Brazils, and from Guade- 

 loupe! . 



Ig. cornuta, Cuv. ; Ig. cornu de St. Dominigue, Lacep. Bonnat. 

 Encycl. Method. Erpetolog. Lezards, pi. iv, f. 4. (The Horned 

 Iguana). Very similar to the Common iguana, and still more so to 

 the preceding species, but is distinguished by a conical osseous point 

 between the eyes, and by two scales raised up over the nostrils; the 

 infra-tympanal plate is deficient as well as the tubercles on the neck, 

 but the scales on the jaws are embossed. 



Ig. cychlura, Cuv. (The Carolina Iguana). Destitute, like the 

 . two preceding species, of infra-tympanal plate or small spines on the 

 ueck, but carinated scales, rather larger than the rest, form cinc- 

 tures on the tail at intervals;];. 



Ophryessa, Bote, 



Have small imbricated scales ; a slightly salient dorsal crest, extending 

 on the tail, which is compressed; denticulated maxillary teeth, and teeth 

 in the palate: all these circumstances approximate them to the Iguang, ; 

 but they have neither dewlap nor femoral pores. 



Lac. superciliosa, L. ; Seb. I, cix, 4 ; Lophyrus xiphurus, Spix, 

 X, so called from a membranous carina, which forms its eye-brow, 

 is an American species, of a fawn-colour, with a festooned brown 

 band along each flank. 



Basiliscus, Dau'J. 



The Basilisks have no pores, but have palatine teeth, like the Ophry- 

 essa; the body is covered with small scales; on the back and tail a con- 

 tinuous and elevated crest supported by the spinous apophyses of the 

 vertebras, like that on the tail of the Istiuri. 



• I have every reason to think that tliis same conclusion should be extended to the 

 Iguanas of Spix, pi. v, vi, vii, viii, and ix: they seem to me to be nothing more than 

 various ages of the common species. 



f I suspect the Amblyrhynclitts cristafiis, Bell. Zool Journ. 1, Supp. p. xii, is a 

 badly prepared specimen of my Ig. nudkoUis. 



X It also appears to me that this Tgiinnn is the same which Dr. Harlan (Journ. 

 Acad. Nat. Sc. of Phil. IV, pi. xv,) calls Cijchhira carbmla; but in this case there 

 must be some mistake, as in the Amblyrhynchus, relative to the palatine teeth. 

 These teeth exist in all my Iguanas. 



