about as long as the praefrontals; frontal a little longer than 

 its distance from the tip of the snout, shorter than the parietals; 

 loreal more deep than long; one prae- and three postoculars; 

 temporals 1+2 or i + 3 ; eight upper labials, third to fifth 

 entering the eye; five lower labials in contact with the ante- 

 rior chin-shields; latter shorter than the posterior. Scales in 

 19 rows, all keeled or those of the outer row smooth; ventrals 

 138 152; anal divided; subcaudals 40 54. 



Brown or reddish-brown above, with a dark network and 

 two longitudinal series of yellow spots or transverse lines; head 

 with small yellow, dark-edged spots; a yellow, black-edged 

 streak on the upper lip, another from the eye to the corner 

 of the mouth; nape dark, with two interrupted yellow trans- 

 verse streaks. Lower surface yellow, uniform or dotted with 

 brown. Length of head and body 325 mm.; tail 75 mm. 



Habitat: Sumatra (Deli!); Singkep Island; Natuna Islands; 

 Borneo (Sandakan Bay!, Baram river, Mt. Dulit, Kuching, 

 Sarawak, Simanggang, Matang!, Tampassuk river, Tandjong). 

 Malay Peninsula. 



15. Tropidonotus trianguligerus Boie. 



Tropidonotus trianguligerus^ Boie, Isis 1827, p. 535. 



Tropidonotus trianguligerus, Boulenger, Cat. Sn. I 1893, p. 224 (s. syn.). 

 Natrix trianguligera, Barbour, Mem. Mus. Comp. Zool. Harv. Coll. XL1V 

 1912, p. 108. 



Eye moderate; rostral scarcely visible from above; inter- 

 nasals trapezoid, as long as or longer than the praefrontals; 

 frontal as long as its distance from the tip of the snout, shorter 

 than the parietals; loreal as long as deep or more deep; one 

 (2) prae- and three or four postoculars; temporals 2 + 2 or 

 2 + 3; nine upper labials, fourth to sixth entering the eye; 

 five lower labials in contact with the anterior chin-shields; 

 latter shorter than the posterior. Scales in 19 rows, strongly 

 keeled, those of the outer row feebly keeled or smooth; ventrals 

 134 150; anal divided; subcaudals 67 105. 



Dark olive above, with small black spots; a lateral series 

 of large, triangular black spots, the points reaching the ventrals 

 and sometimes forming bands across the belly, separated by 

 red interspaces; on the posterior part of the body the spots 

 are indistinct; upper labials yellow, with black sutures. Lower 



