240 IGUANIDA. 
Head-spines moderately large; gular scales 
feebly keeled. . 22 keesacesa<esgeeess 3. boucardii, p. 243. 
II. Nostril pierced in the line of the canthus rostralis or slightly 
above; several longitudinal series of enlarged gular scales; a 
series of very large bony shields below the lower labials. 
Occipital spines obliquely directed upwards, 
like the temporals; ventralscales smooth. 4. coronatum, p. 243. 
Occipital spines vertical, erect; ventralscales 
ROCIO: 2:.6-600-2 Gu G8 eg ech goatee HL 5. asio, p. 244. 
III. Nostrils pierced within the canthi rostrales ; gular scales small, 
equal, or with one series of enlarged ones on each side. 
A. Tail longer than the head. 
1. Head bordered posteriorly by a 
series of contiguous large spines, of 
which four are occipital ........ 6. regale, p. 245. 
2. Two occipital spines, larger than the other head-spines, with 
an interval between their bases and those of the temporals. 
Enlarged dorsal tubercles spinose, erect ; 
tympanum naked .................. 7. cornutum, p. 245. 
Enlarged dorsal tubercles flat or feebly 
raised; tympanum covered with scales ; 
occipital spines as long as the horizontal 
diameter of the orbit................ 8. maccallii, p. 246. 
Enlarged dorsal tubercles flat or feebly 
raised ; tympanum covered with scales ; 
occipital spines shorter than the hori- 
zontal diameter of the orbit ......... . 9. platyrhinus, p. 247. 
3. Two occipital spines, not longer 
than the longest temporals ...... 10. modestum, p. 248. 
B. Tail not longer than the head. 
Occipital spines a little larger than the 
temporal, - ico aee dea ek ee 4 11. braconnieri, p. 248. 
Occipital spines much smaller than the 
largest temporals .......... ....... 12. taurus, p. 249. 
1. Phrynosoma douglassii. 
Phrynosoma douglassii, Gray, Cat. p. 227. 
Agama douglassii, Bell, Trans. Linn. Soc. xvi. 1833, p. 105, pl. x.; 
Harlan, Med. & Phys, Res. p, 141, pl. —. tig. 3. 
Phrynosoma douglassii, Wagl. Syst. Amph. p. 146; Wiegm. Herp. 
Mex. p. 54; Holby, N. Amer, Herp. ii. p, 101, pl. xiv.; Girard, 
in Stansb. Exped. Gr. Salt Lake, p. 362, pl. vii. figs. 6-9; Cope, 
Proc. Ac. Philad. 1866, p. 302; Coues, in Wheeler's Rep. Laplor. 
W. 100th Mer. v. p. 591. 
orbiculare (non LZ.), Hallow. in Sttgr. Exped. Zuni § Color, Riv. 
p. 125, pls. vill. & ix. 
