43. TANTILLA 879 
rather broad across temporal region, little distinct from neck. 
Eye small. Rostral rather large, broader than high, and 
bounded behind by internasal, anterior nasal and first labial 
plates. Plates on top of head are a pair of small internasals, 
a pair of prefrontals, a frontal, the supraocular of each side, 
and a pair of parietals. Posterior nasal in contact with pre- 
ocular. No loreal. One preocular. Two, or rarely 
one, postoculars. Temporals elongate, 1+1. Supra- 
labials seven, the last largest, the third and fourth 
reaching eye. Infralabials seven, the first pair not meeting 
on the midline. Anterior genials longer than posterior. 
Scales smooth, in 15 rows. Anal divided. Gastrosteges 
varying in number from 135 to 148. Urosteges in two 
series of from 51 to 64. 
The general color above is pale brownish or yellowish 
gray, unicolor. The upper surface of the head is dark 
brownish gray becoming blackish brown posteriorly. All of 
the specimens show a more or less well marked whitish nuchal 
collar from one to three rows of scales behind the parietals. 
This collar is from one to one and a half rows of scales 
wide and is not edged with darker posteriorly. The lower 
surfaces are coral red, becoming grayish white in alcohol. 
In a living specimen the upper surfaces, except of the 
head, were unicolor, light yellowish hair-brown or brownish 
straw. The upper surface of the head was dark olive, be- 
coming blackish brown posteriorly. The labials, lower sur- 
face of head, and neck to the sixth gastrostege, the tips of 
all the gastrosteges, and two or three rows of lateral scales 
on each side, were grayish white. The rest of the lower 
surfaces from the sixth gastrostege to the tip of the tail were 
bright coral red. 
Icength’ ‘toanus._._- 104 130 138 149 160 168 
Tenpthicofstail 2) 3 33 50 44 55 49 55 
