682 13. COLUBRID 
tinct. Loreal rather large, with no small plate below it. 
Preoculars two, upper much larger than lower. Postoculars 
two, nearly equal. Temporals two followed by two. Eight 
superior and nine or ten inferior labials, seventh upper and 
fifth lower largest, fourth and fifth upper reaching eye, first 
pair of lower meeting on median line. Genials in two pairs, 
posterior much larger than anterior. Scales on body smooth, 
in 17 rows. Anal plate divided. Gastrosteges 193. Uros- 
teges in two series of 130. Tail very long and slender. 
The color above, including the tips of the gastrosteges 
and urosteges, is dark grayish olive brown, palest on the 
head and tail. A single white line extends along each side, 
on the third and fourth rows of scales, onto the base of the 
tail. This line is narrowly bordered with black, and shows 
slight enlargements at intervals of from four to seven scales, 
on the anterior half of the body. The sides of the head are 
spotted with white. The upper portions of the supralabials 
are blackish brown. The lips, chin and throat are white, 
without dark markings, but faintly washed with pink. The 
anterior gastrosteges are suffused with rose pink. The 
other lower surfaces are yellowish white with faint gray 
cloudings laterally. 
Henteth toy, ani $s ee —774 
hengthtotetall 22—Se 374+ 
Remarks.—This species is closely related to both Colu- 
ber lateralis and Coluber aurigulus. The only specimen 
known is an adult female. 
Distribution.—This snake was found on Isla Partida, 
Espiritu Santo Island, Gulf of California, Mexico, May 30, 
NOP 
