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 1 o r e a 1. 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. 



Length to anus 104 130 138 149 160 168 



Length of tail 33 50 44 55 49 55 



