40. THAMNOPHIS 



frontals, a frontal, supraocular of each side, a pair of parie- 

 tals. Anterior and posterior nasals distinct. One loreal. 

 One or rarely two preoculars. Two to four, normally three, 

 postoculars. Temporals normally one followed by two, 

 sometimes 1+3 or 1 + 1. Eight (rarely seven, nine or six), 

 superior and ten (rarely eight, nine or 11), inferior labials, 

 usually the sixth in each series largest, the fourth and fifth 

 superior reaching eye, first pair of inferior meeting on 

 median line. Two pairs of genials, posterior equal to or 

 shorter than anterior. Scales on body in 2 1 or 19 rows, all 

 keeled. Anal plate not divided. Gastrosteges varying in 

 number from 151 to 179, males having from 159 to 179, 

 females from 151 to 175. Urosteges in two series of from 

 70 to 101, males having from 78 to 101, females from 

 70 to 88. 



The back is dark brown or blackish, with no, or but little, 

 evident spotting. Dorsal and lateral light stripes are pres- 

 ent. The dorsal stripe is narrow, usually about the width 

 of one or one and two half scales, and has well defined 

 straight edges. The gular region and the lower surfaces 

 of body and tail are yellowish or greenish white, rarely 

 much clouded with darker. 



A specimen showing the colors in life is described by 

 Dr. Grinnell as follows: "Ventrally the snake is pale green- 

 ish blue, the distal margins of the gastrosteges becoming 

 pinkish. The throat, sides of head, and snout, are dull 

 pinkish. Dorsally the snake is almost black, more exactly, 

 perhaps, sooty sepia. A conspicuous median dorsal straw- 

 yellow line runs from the nape to the tip of the tail, 

 though on top of the tail it becomes narrow and faint. This 

 stripe involves the median scale row, and part of the one on 

 either side, especially anteriorly. A small spot of yellow 

 marks the top of the head, involving the median margins 

 of the two parietal plates. Along each side of the snake its 



