Scalation that of typical colubrid (see Pl. 19); rostral large, extending back onto dorsal surface of snout, bluntly pointed behind; paired internasals considerably wider than long, convex anteriorly, almost straight-edged posteriorly, each extends laterally to naris; paired prefontals approximately twice size of internasals, and wider than long, extending laterally on each side to level of nostril; frontal convex anteriorly, concave on each side, bluntly pointed behind, nearly twice as wide anteriorly as posteriorly; parietals large; angle formed between them by frontal slightly more than 90 degrees; nostril large, situated between almost equal sized anterior nasal and posterior nasal plates; loreal slightly smaller than nasals, its anterior edge inclined forward superiorly; two rows of temporals on each side; in upper row, first one narrow and elongate, second much shortened, third intermediate in shape; in lower row all three approximately alike in size and shape; two postoculars, the lower larger; seven supralabials, first small and low, longer along upper edge than along lower, second slightly longer than high, third higher than long, contacting eye; fourth largest, contacting posterior part of eye, and lower postocular; fifth nearly as large, pointed above; sixth also large, pentagonal; seventh low and rectangular; on chin first pair of infralabials separate mental from anterior genials; second infralabial minute; third approximately twice its size; fourth much smaller, rhomboidal, fifth also large, pentagonal; sixth smaller, rhomboidal, bluntly pointed behind; seventh smaller, narrow behind; eighth small and elongate; second pair of genials longer and narrower than those of first pairs, separated from each other by smaller scales; genials in approximately five rows, but somewhat irregular in arrangement, mostly smaller and narrower than body scales; latter all smooth, arranged in 17 rows for about two-thirds of body length, then, by loss of third row on each side, reduced to 15; scales of neck region rounded and relatively small, one-third to one-fourth size of larger body scales; lowest scale row on each side largest with its scales much wider and less symmetrical than others; most of body scales of approximately hexagonal shape; on forebody they average approximately twice as long as wide, but farther posteriorly on body, width-length ratio gradually increases and some of scales, notably those of lowest row, approximately as wide as long; regularity of scale rows broken on sides just above vent by presence of many small additional scales; on tail scale rows drop out posteriorly in rapid succession, until on posterior third only four are present; ventrals strongly convex posteriorly, with free posterior edges, nearly half length of scales; anal plate divided, with diagonal suture; subcaudals in double series, those of right and left sides alternating; several minute subcaudal-like scales on each side of vent. _Dentition_