40. THAMNOPHIS 813 



Thamnophis ordinoides ordinoides RUTHVEN, Bull. U. S. Nat. Mus., 

 No. 61, 1908, p. 147 (part); STEJNEGER & BARBOUR, Check List 

 N. Amer. Amph. Rept., 1917, p. 101; GRINNELL & CAMP, Univ. 

 Cal. Publ., Zool., Vol. 17, No. 10, 1917, p. 179 (part); VAN DEN- 

 BURGH & SLEVIN, Proc. Cal. Acad. Sci., Series 4, Vol. VIII, No. 6, 

 1918, p. 215, pi. 8. 



Description. Head distinct from neck, flat-topped, with 

 narrow, rounded snout, and temporal regions sometimes 

 slightly swollen. Eye small. 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, rarely absent. One or two preoculars and three or 

 rarely two postoculars. Temporals normally two followed 

 by two, sometimes 1 + 1 or 1+3. Superior labials normally 

 seven, rarely six, eight or five. Inferior labials normally 

 eight, rarely nine, seven, six or five. Usually the fifth or 

 sixth superior and fourth, fifth, or sixth inferior labials 

 largest, third and fourth or fourth and fifth superior 

 reaching eye, first pair of inferior meeting on median line. 

 Two pairs of genials, posterior longer than anterior. Scales 

 on body in 17 or 19 rows, all keeled except sometimes the 

 first row of each side. Anal plate not divided. Gastrosteges 

 varying in number from 136 to 162, males having from 

 138 to 162, females from 135 to 154. Urosteges in two 

 series of from 50 to 81, males having from 56 to 81, 

 females from 50 to 72. 



The ground color above is olive or pale blackish brown, 

 dotted and spotted with black along the edges of the scales, 

 and with or without three light longitudinal lines. The 

 lateral lines, when present, are usually grayish or greenish 

 blue, while the dorsal line which often fades out poster- 

 iorly may be white, gray, blue, yellow, or brick red. A 



