1885.] NATURAL SCIENCES OF PHILADELPHIA. 145 



spinous ; tail of medium length, similar to the body, and margined 

 with conical scales. 



Habitat. — Tehuantepec, Mexico. 



This large and beautiful species is most nearly allied to coro- 

 natam, from which it is separated by the character of the cephalic 

 spines, and also that of the abdominal scales. It is also closely 

 related to the succeeding species, differing, however, in the posi- 

 tion of the nostrils, and in the number and position of the rows 

 of enlarged gular scales. 



6. Phrynosoma cornutum. 



Agcnna comuta Harlan, Journal Acad. Nat. Sci. Phila., iv, 1825, p. 

 299, pi. xx. 



Lacerta comuta Cuv., Regn. Anim., 2d edit., ii, 1819, p. 37. 



Phrynosoma cornutum Gray, Griff. Anim. King., ix, 1831, p. 45 ; Hol- 

 brook, N. Am. Herp., ii, 1842, p. 87, pi. xi ; Dekay, Zool. New York, 

 iii, 1842, p. 31; Gray, Cat. Liz. Brit. Mus., 1845, p. 229; Girard, 

 Stans. Expl. Vail. Gt. Salt Lake, 1852, p. 360, pi. viii, figs. 1-6 ; 

 Blanchard, Organ. Regn. Anim., 1852, pt. v, pi. xii ; Hallowell, Sit- 

 greaves' Exped. Zuni and Col. Rivers, 1853, p. 119 ; Girard, Herp. 

 U. S. Expl. Exped., 1858, p. 403, pi. xxi, figs. 6-9 ; Baird, U. S. and 

 Mex. Bound. Surv., pt. ii, 1859, p. 9 ; Dumeril & Bocourt, Miss. Sci. 

 au Mex. et Am. Cent., Rept., 1870, p. 236, pi. xii, fig. 9 ; Cope, Check 

 List N. A. Batrach. and Rept., 1875, p. 49 ; Yarrow, U. S. Geol. 

 Surv. west of 100th Meridian, v, 1875, p. 579 ; Midler, Verh. Nat. 

 Gesell., Basel, 1878, p. 634 ; Cope, Proc. Am. Phil. Soc, 1879, p. 261; 

 Cope, Bull. U. S. Nat. Mus., No. 17, 1880, p. 17. 



Phrynosoma Harlani Wiegmann, Herp. Mex., i, 1834, p. 54 ; Dumeril 

 & Bibron, Erpet. gener., iv, 1837, p. 314 ; Spring & Lacordaire, 

 Bull. Acad. Roy. Brussels, 1842, pt. ii, p. 192, fig. 2 ; Aug. Dumeril, 

 Cat. Meth. Coll. Rept. Mus. Paris, 1851, p. 28. 



Tropidogaster cornutus Fitzinger, Sys. Rept., i, 1843, p. 79. 



Phrynosoma planiceps Hallowell, Proc. Acad. Nat. Sci. Phila., 1852, p. 

 178 ; Hallowell, Sitgreaves' Exped. Zuni and Col. Rivers, 1853, p. 124, 

 pi. vii ; Dumeril, Arch. Mus. Hist. Nat., viii, 1855, p. 552 ; Dumeril 

 & Bocourt, Miss. Sci.au Mex. et Am. Cent., 1870, p. 238, pi. xii, 

 fig. 11 ; Cope, Check List N. A. Batrach. and Rept., 1875, p. 49 ; 

 Yarrow, TJ. S.Geol. Surv. west of 100th Meridian, v, 1875, p. 579, 

 pi. xxiv, fig. 1 ; Coues, in the above, p. 593. 



Head broad ; nostrils anterior, placed Avithin the superciliary 

 ridges ; cephalic spines strongly developed ; occipital spines long, 

 directed obliquely upward, a smaller spine between the two ; pos- 

 terior inframaxillary plates largest ; one row of enlarged pointed 

 gular scales on each side, distant from the median line ; two rows 



11 



