CROCODILIANS, LIZAKD8, AND SNAKES. 



419 



The typical form lias beeu received at the Museum of Paris from the 

 States of Vera Cruz and Pueblo, and from the Mexican Plateau. Our 

 s])e('imens are, from the northern plateau at Chihuahua and southern 

 Arizona. The var. A came from the high lands of Vera Cruz, aud the 

 var. 13 from Colima, on the west coast. 



I'hrynoHoma ovhicnlare U'ie</)iuinn. 



PHRYNOSOMA BOUCARDII Bocourt. 



rhrynosoma boucardii Boulenger, Cat. Liz. Brit. Mus., 2d ed., II, 1885, p. 243. 

 Tajxiya hoKcardii Au(;. Dumekil and Bocoukt, Miss. Sci. Mex., 1870, pi. xi, 

 figs. 4, 4a; Pt. 3, 1874, p. 225. 



Head, thick; wider than long. Cephalic spiues of moderate length; 

 those of the occiput directed obliquely upward, a little more prolonged 

 backward than the longest ones of the temporal region. Numerous 

 occipital tubercles. Trihedral scales of the body projecting. Abdom- 

 inal scales smooth. Head with top relatively narrow, not equal half 

 its greatest length ; the contour from the end of the muzzle to the super- 

 ciliary angle a little curved oblique line. Inframaxillary scutella rec- 

 tangular, a little smaller than the post«rior sublabials; one conical, 

 pyramidal scale at the junction of the lips; nostrils pierced on the pro- 

 longed superciliary ridge; auricular o])ening bordered anteriorly with 

 small projecting scales; occipital plate distinct, oval, and followed by 

 numerous conical scales; upper part of the body bristling with project- 

 ing trihedral tubercles. Eleven to fourteen pores on the inner side of 

 the thigh; tail about two-fifths the length of the animal and character- 

 ized in the males by a little greater length, a thicker base, and by two 

 postanal scales somewhat larger than the others. A fringe around the 

 l)eriphery of the ab<lomen formed of twenty-six or twenty-seven large 

 trihedral, subpyramidal scales; four similar scales over each arm; length 

 of tibia equal to the distance between the end of the snout and the 

 beginning of the occipital spines; scales of the belly and the under- 

 side of tlu^ tail smooth; those of the throat feebly keeled. 



Ground color ocher yellow, with four brown spots extending on both 

 sides of the vertebral line; the one on the neck large and rounded, the 

 three others, on the trunk, subrectangular, with bright yellow poste- 

 rior borders; legs and tail crossed by similar brown bands; head and 

 cephalic spines sienna brown. Underside yellowish, with rounded 

 blackish spots scattered far apart. 



I'lui/nosoma boucardii^ like riiri/nosoma orhiculare,hiiS a var. A, head 

 wider than long, but it is easy to distinguish the latter by the following 



