55 



PHRYNOSOMA .—Weigmann. 



Genus Phrynosoma. — Characters. Head short, rounded anteriorly, bordered 

 laterally and posteriorly with strong spines, and covered above with polygonal 

 nearly equal sized scales; occipital plate semicircular; palate teeth wanting. 



PHRYNOSOMA CORNUT A. —^ar/aM. 



Plate IX. 



Characters. Head short, thick, triangular, rounded in front, with a range of 

 long spines on each side of the lower jaw — nostrils open within the internal margin 

 of the superciliary ridge; body short, flattened, rounded, covered with triliaedral 

 tubercles, intermixed with small imbricated scales; abdomen flattened, and covered 

 with rhomboidal carinated scales; femoral pores, but not well developed. 



Synontmes. Lacerta tapayaxin, Bart., Med. and Phys. Jour., vol. iii. part ii. p. 68. 

 Agama cornuta, Harl., Jour. Acad. Nat Scien. Philad., vol. iv. p. 299, pi. xx. 

 Tapaya orbicularis, Cuv., Reg. An., torn. ii. p. 37. 

 Phrynosoma cornuta, Gray, in Griff. An. King., vol. ix. p. 45. 

 Phrynosoma harlani, JVeig., Herp. Mex., pars i. p. 54. 

 Phrynosoma harlani, Dum. et Bibr., Hist. Nat. des Rept., torn. iv. p. 315. 

 Horned toad, Vulgo. 



Description. The head has nearly the form of an equilateral triangle, rounded 

 at the snout, and covered on the verte.x with small polygonal scales, all nearly of 



