16. HE LODE RM A 471 



Genus 16. Heloderma 



Heloderma WIEGMANN, Isis, 1829, p. 264 (type, horrUum). 



There are four pentadactyle limbs. The head is cov- 

 ered with irregular, convex, bony plates, which often cdos- 

 sify with the skull. The back and sides are provided with 

 more or less regular rows of tubercles similar to those on the 

 head. The ventral plates are arranged in transverse series. 

 The eye has well-developed lids and a round pupil. The 

 ear-openings are large. One strong and usually one or 

 more weaker gular folds are present. 



97. Heloderma suspectum Cope 



GILA MONSTER 

 Plates 44, 45, 46, 47 and 48 



Heloderma horridum BAIRD, U. S. Mex. Bound. Surv., Vol. II, Rcpt., 

 1859, p. 11, pi. 26; BAIRD, Kept. Pac. R. R. Surv., Vol. X, 1859, 

 p. 38; COPE, Proc. Acad. Nat. Sci. Phila., 1866, p. 303; COOPER, 

 Proc. Cal. Acad. Sci., Vol. IV, 1870, p. 67. 



Heloderma suspectum COPE, Proc. Acad. Nat. Sci. Phila., 1869, p. 5 (type 

 locality, Sonoran Region); COPE, Bull. U. S. Nat. Mus., No. i, 

 1875, p. 47; YARROW, Surv. W. looth Merid., Vol. V, 1875, p. 562; 

 COUES, Surv.W. looth Merid., Vol. V, 1875, p. 601; BOCOURT, Miss. 

 Sci. au Mex., Rept., 1878, p. 297, pis. XXE, figs. 1-12, XXG, figs. 

 i, 3, 6-1 1 ; YARROW, Bull. U. S. Nat. Mus., No. 24, 1883, pp. 9, 48; 

 BOULENGER, Cat. Lizards Brit. Mus., Vol. II, 1885, p. 302; STEJ- 

 NEGER, N. Am. Fauna, No. 7, 1893, p. 194; COPE, Amer. Naturalist, 

 Vol. XXX, 1896, p. 1014; VAN DENBURGH, Occas. Papers. Cal. Acad. 

 Sci., V, 1897, p. 120, fig.; HERRICK., TERRY & HERRICK, Bull. Sci. 

 Lab. Denison Univ., Vol. XI, 1899, P- I 44? HERRICK, TERRY & 

 HERRICK,^ Bull. Univ. New Mexico, Vol. I, 1899, p. 144; Me LAIN, 

 Critical Notes, 1889, p. 8; COPE, Report U. S. Nat. Mus. for 1898, 

 1900, p. 476, fig. 87; BROWN, Proc. Acad. Nat. Sci. Phila., 1903, 

 p. 552; DITMARS, Reptile Book, 1907, p. 172, pi. LIV; RUTHVEN, 

 Bull. Amer. Mus. Nat. Hist., Vol. XXIII, 1907, p. 555; VAN DEN- 

 BURGH & SLEVIN, Proc. Cal. Acad. Sci., Ser. 4, Vol. 3, 1913, p. 406; 

 STEJNEGER & BARBOUR, Check List N. Amer. Amph. Rept., 1917, 



