97 



PHRYNOSOxMA COROlSi AT A.— Bkdnvilk. 



Plate XIII. 



Characters. Head short, triangular; nostrils open at the anterior extremity 

 of the superciliary ridge; occipital region surrounded with eleven spines; eight 

 rows of large, rhomboidal, elongated and pointed scales under the chin, reaching 

 to the throat, external series largest. Body covered with rhomboidal scales, and 

 large trihedral tubercles; two rows of spines along the flanks, the superior larger; 

 a row of spines on each side the tail, from the root to the extremity. 



SrNONYMES. Phrynosoma coronata, Blainville, Nouv. Ann. du Mus. d'Hist. Nat., torn, 

 iv. p. 2S4, pi. XXV. fig. 1. a b c. 

 Agama orbicularis, Jiudiibon, Birds, &c., vol. iv. pi. ccclxviii. 

 Phrynosoma coronata, Dumeril et Bibron, Hist. Nat. des Rept., torn. iv. p. 31S. 



Description. The head is short, thick, triangular, and covered on the forehead 

 and vertex with small polygonal plates of miequal size, and with a few scales and 

 elevated tubercles on the occipital region. The snout is short and rounded, Avith 

 the rostral plate very small. The nostrils are near the snout, open at the anterior 

 extremity of the superciliary ridge, and are directed upwards and a little out- 

 wards. The nasal plates are single on each side, circular, exceedingly narrow, 

 and surrounded by six polygonal scales. The superciliary ridge is prominent, 

 projecting over the eye, and covered with five or six quadrilateral plates; poste- 

 riorly it is elongated, and terminates in a pointed tubercle. The ej^es are small 

 and sunken, with the pupil black and the iris very dark grey. The superior labial 

 plates are eight in number, quadrilateral, very small, and not extending to the 

 angle of the mouth, where their place is supplied by small granulations; there are 

 Vol. II.— 13 



