246 



IGUANID^. 



outwards. A series of very large projecting scales below the lower 

 labials ; gular scales keeled, with a longitudinal series of enlarged 

 pointed ones on each side ; two or three groups of spines on each 

 side of the neck; gidar folds several, irregular. Back with very 

 large erect spinose tubercles, the largest of which form a series of 

 three or four on each side of the vertebral line ; two lateral series 

 of spines, upper largest; pectoral and ventral scales more orjess^^j^^ 

 distinctly keeled. Femoral pores four to twelve on each sidernot 

 extending on the praeanal region, sometimes very indistinct. No 

 enlarged postanal scales. Tail once and a half to twice and a half 

 as long as head and b<=>dy. Greyish or brownish above, with a more 

 or less marked light dorsal streak and dark brown spots at the base 

 of the larger dorsal spines ; a large dark brown spot on each side of 

 the nape ; two cross streaks between the supraciUary ridges, a band 

 from the eye to the angle of the mouth, and another from the eye to 

 the middle temporal spine, dark brown ; lower surfaces yellowish, 

 uniform or with a few small brownish spots. 



millim. 



Total length 125 



Head 21 



Width of head .... 21 

 Body 64 



United States ; Northern Mexico. 



millim. 



Fore limb 47 



Hind limb 59 



Tail 40 



Phrynosoma planiceps, Hallow. Proc. Ac. Philad. 1852, p. 178, and 

 in Sitgr. Exped. Zuni ^- Color. Riv. p. 124, pi. vii. ; £ocoin-t, I. c. 

 p. 238, pi. xii. fig. 11 ; Yarrow, in Wlieeler's Beport Explor. W. 

 100th Mer. p. 579, pi. xxiv. fig. 1. 



Hardly distinguishable from P. cornutum. Ventral and gular 

 scales smooth. 

 Texas to Sonora. 



8. Phrynosoma maccallii. 



Anota m'callii, Hallow. Proc. Ac. Philad. 1852, p. 182, and in Sitgr. 

 Exped. Zuni ^- Color. Riv. p. 127, pi. x. ; Bocourt, Miss. Sc. Me.r., 

 Rept. p. 230. 



