44 University of California Publications in Zoology [Vou.9 
Phrynosoma platyrhinos Girard 
Desert Horned Lizard 
Doliosaurus platyrhinos Girard (1858), p. 409. 
Phrynosoma platyrhinum Cope (1888), pp. 15, 18. 
Phrynosoma platyrhinus Boulenger (1885), p. 247. 
Anota platyrhina Cope (1898), pp. 443-447, fig. 81. 
Anota calidiarum Cope (1896), pp. 833-836. 
Phrynosoma calidiarum Ditmars (1907), p. 157. 
( Es 
‘pps <..premax. 
supratemp. op.-<--- 
pin. for» 
Fig. E. Skull of Phrynosoma platyrhinos (Uniy. Calif. Mus. Vert. 
Zool., no. 1301). dent., dentary; fron., frontal; jug., jugal; maz., maxil- 
lary; nas., nasal; nas. op., nasal opening; occ. h., occipital horn; orb., orbit; 
par., parietal; pin. for., pineal foramen; prefron., prefrontal; premaz., pre- 
maxillary; postorb., postorbital; swpraocc., supraoccipital; supratemp., 
supratemporal; supratemp. op., supratemporal opening; temp. h., temporal 
horn. X 2. 
EXTERNAL CHARACTERISTICS 
Diagnostic Characters —Head short and wide; occipital horns 
of medium size (4-9 mm.), flattened and grooved and but little 
longer than the temporals; interoccipital represented by an en- 
larged scale; nostrils above the line joining the superciliary 
ridge with the end of the snout; temporal horns five to seven 
on each side, the larger posterior ones pointing in almost the 
same direction as the occipitals; head plates grooved and ridged 
and nearly equal sized, except for three enlarged seales in front 
of the occipital horns; sublabials large and spinose, increasing 
in size posteriorly; no enlarged infrarictal spine; usually one 
row of enlarged gular seales on each side, distant from the 
