SYNOPSES AND DESCRIPTIONS. 125 



rostral angles sharp; tail short, near one seventh of the total, tapering to 

 a slender extremity. Eye moderate, pupil erect. Anterior portion of the 

 nasal larger. Rostral higher than wide. A pair of small internasals, 

 commonly in contact; a similar shield over each loreal in contact with 

 the former. Labials eight (7- — 8), separated from the orbit by one or two 

 scales, second entering the pit, posterior small. Infralabials ten, anterior 

 pair large, in contact. Submentals two pairs, posterior smaller, and sepa- 

 rated by smaller plates. Scales elongate, keeled, in 25 (23 — 25) rows, 

 outer a little broader. Ventrals broad, 199 — 205. Anal entire. Sub- 

 caudals 60 — 71 pairs. 



Olivaceous, greenish or yellowish; dark-clouded to uniform yellowish 

 below. With scattered transverse dark-edged bands of brown, sometimes 

 divided along the vertebral row of scales, and tending toward alternation. 

 The variation in respect to marking is very great in this species. Instead 

 of transverse bands some specimens have triangles on the flanks. Others 

 have the bands much broken, sometimes forming dorsal and lateral series 

 of spots more or less irregular. Generally the bands are separated by 

 spaces much wider than themselves. A dark band from the eye to the 

 neck. Light-colored specimens show a lighter border to the spaces be- 

 tween the bands ; often the center of the space is dark. Brazil to Central 

 America, possibly to Mexico. 



Trigonocephalus affinis. 



BoTHRors affinis Bocourt, 1868, Ann. Sci. Nat, 201. 



Nasal divided; subcaudals simple; second labial not forming the ante- 

 rior border of the lachrymal fosse; rostral triangular, apex rounded, not 

 separated from the nasal by a row of scales ; supraciliary long and narrow. 

 Nine or ten labials, fifth largest, and separated from the orbit by four rows 

 of scales. Back with twenty-three to twenty-five rhomboidal spots. 



Resembling Teleurasjns nummifer, but distinguished by a more elongate 

 form, the rostral in contact with the nasals, instead of being separate by 

 a single row, the longitudinal development of the supraciliaries, and the 

 greater number of rhomboidal spots. The spot beneath the eye is charac- 

 teristic, Scales in 27 rows. Guatemala. 



