40. THAMNOPHIS 853 
Thamnophis megalops Rutuven, Bull. U. S. Nat. Mus., No. 61, 1908, 
p- 44; Van Densurcu & Srevin, Proc. Cal. Acad. Sci., Ser. 4, 
Vol. II, 1913, p. 421; Sreynecer & Barsour, Check List N. 
Amer. Amph. Rept., 1917, p. 101; Van DensurcH & S Evin, 
Proc. Cal. Acad. Sci., Ser. 4, Vol. VIII, 1918, p. 283, pl. 15. 
Description—Head distinct from neck, flat-topped, 
with narrow, rounded snout, and temporal regions not in- 
frequently swollen. Eye large. Rostral large, bounded 
behind by internasal, anterior nasal, and first labial plates. 
Plates on top of head: a pair of internasals, a pair of pre- 
frontals, a frontal, supraocular of each side, and a pair of 
parietals. Anterior and posterior nasals distinct. One 
loreal. One preocular, and three or four postoculars. Tem- 
porals one followed by two or three. Eight (rarely nine) 
superior and 10 (rarely nine or 11) inferior labials, sixth 
in each series usually largest, fourth and fifth superior reach- 
ing eye, first pair of inferior meeting on median line. Two 
pairs of genials, the posterior usually longer than anterior. 
Scales on body in 21, or rarely 23, rows. Anal plate not 
divided. Gastrosteges in Arizonan specimens varying in 
number from 154 to 165. Urosteges in two series of from 
72 to 77. 
The color above is olive or brown with three more or less 
distinct longitudinal light lines. The dorsal line varies 
considerably in width. The lateral line is on the scales of the 
third and fourth rows anteriorly, of the third or second and 
third posteriorly. Specimens with a light ground color show, 
more or less definitely, two series of dark spots between the 
dorsal and lateral lines, the spots of the upper series rather 
more indefinite than those of the lower, with which they 
alternate. In dark specimens these may be obscured. The 
longitudinal lines are yellow or yellowish white. Dark 
nuchal blotches are present. The labials are light olive or 
yellow with dark posterior edges. A light postoral crescent 
