410 SAURIA. 



apertures either extant or absent. Mental scales very small, equal. 

 Pectoral scales small, subrhombic, and subcarinated. No pyramidal 

 scales in series at the periphery of the abdomen. Abdominal scales 

 small, and slightly carinated. Femoral pores distant, constituting 

 a continuous series across the interfemoral region. Brownish-olive 

 above, maculated with black ; beneath yellowish-white, unicolor. 



SYN. Phrynosoma modestum, GRD. in Stansb. Expl. Vail. Gr. Salt Lake, Utah, 

 1852, 361 & 365. PI. vi, figs. 4-8. 



OBSERV. The body has rather a smooth appearance, owing to the 

 diminutiveness of the tubercular scales, and the entire absence of the 

 pyramidal ones from the periphery of the abdomen. The mental scales 

 are very small and equal, as in Phrynosoma, properly so called. The 

 cephalic spines resemble those of D. platyrldnos most, though some- 

 what less developed. The auricular apertures are seldom fully deve- 

 loped : sometimes, the right is developed and the left obliterated, or 

 else it is the reverse ; most generally, they are either entirely or 

 partially obliterated. The tail is very slender and subconical. 



Loc. Valley of the Rio Grande del Norte (Rio Bravo) . 



SCBFAM. ACRODONTES. 



The maxillary teeth are soldered fast upon the free and even edge 

 of the jaw bones. The body is either depressed or broader than deep, 

 else compressed or deeper than broad. A dorsal crest in some genera ; 

 absent in others. Palatine teeth are always wanting. 



SYN. Acrodontes, WAGL. Naturl. Sjst. Amph. 1830, 144 & 150. DUM. & BIBR. 

 Erpet. g6n. IV, 1837, 375. DUM. & A. DUM. Catal. meth. Kept. Mus. d'hist. nat. i, 

 1851, 86. 



OBSERV. The remarks made under the heading of the Pleurodontes 

 (page 313), will equally apply to the Acrodontes. The latter are all 

 inhabitants of the Old World. 



