240 TGTJANIDJE. 



Head-spines moderately large ; gular scales 



feebly keeled 3. boucctrdii, p. 243. 



II. Nostril pierced in the line of the cauthus 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 ; ventral scales smooth. 4. coronatum, p. 243. 

 Occipital spines vertical, erect; ventralscales 



keeled 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 s])ines 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. platyrliinus, p. 247. 



3. Two occipital spines, not longer 



than the longest temporals 10. modestam, p. 248. 



B. Tail not longer than the head. 



Occipital spines a little larger than the 



temporals 11. hraconnieri, p. 248. 



Occipital spines much smaller than the 



largest temporals , 12. taurus, j). 249. 



1. Phrynosoma douglassii. 



Phrynosoma douglassii, Gray, Cat. p. 227. 



Agama douglassii, Bell, Trans. Linn. Sue. xvi. 1833, p. 105, pi. x. ; 

 Harlan, Med. ^- Phijs. Res. p. 141, pi. — . tig. 3. 



Phrynosoma douglassii, Wafjl. Syst. AmpJi. p. 146 ; Wiegm. Herp. 

 Mex. p. 54; Ilolhr. N. Amer. Herp. ii. p. 101, pi. xiv. ; Girard, 

 in Stansb. E.vped. Gr. Salt Lake, p. 362, pi. vii. figs. 6-9 ; Cope, 

 Proc. Ae. Philad. 1866, p. 302 : Cones, in Wheeler s Hep. E.iplor. 

 W. 100 fh Mer. v. p. 591. 



■ orbiculare (non L.), Hallotc. in Sityr. Exped. Zuni Sf Color. Pit: 



p. 125, pis. viii. >S: ix. 



