187 



which border the cleft of the mouth. Lower labials 11. Scales in 17 

 rows, keeled and covered with very narrow stripes. 



25. Lepidognathus rugosus n. sp. (plate XVI, flg. 1, 2, 3, 4 and 5). 

 Sumatra: Kaju tanam, 1 spec. 



The only specimen of this species has the upper part of the head 

 and the back of an olive-colour, whüst the margins of the scales are 

 whitish; the underparts of the head, the anterior upper-labials , the 

 ventrals, the outer row of scales and the lower half of the penulti- 

 mate row are yellow. 



A fold behind the nostril runs straight through the nasal, thus as 

 it were dividing it into two parts. The nasals rest on the two anterior 

 and a part of the third upper-labial , they are separated by two al. 

 most crescent-shaped anterior frontals, which form together a triangle 

 with a rounded top. The three-sided loreal rests on the anterior part 

 of the flfth, on the fourth and on the posterior part of the third 

 upper labial; the pretty large praeocular on the posterior part of the 

 fifth upper-labial. The small scales below the orbit, three in number, 

 rest on the sixth , seventh , eighth and ninth upper-labials. The tenth 

 upper-labial touches the ürst of the temporals, whilst the eleventh 

 and the twelfth upper-labials, greatly inferior in height to the ten 

 preceding ones, are in contact with the posterior temporals. There is 

 a longitudinal groove between the ten anterior upper-labials and the 

 shields above them. The third, fourth, flfth, sixth, seventh, eighth, 

 ninth and tenth upper-labial are resting on a row of small trigonal 

 scales which border the cleft of the mouth. 



The five-sided vertical is as broad as high, and is bordered on both 

 sides by the supraciliaries, that of the left side being divided into 

 two shields. The postocular closes the ring round the orbit formed by 

 the supraciliaries, the praeocular and the three small shields below 

 the eye. 



The mental shield is rather narrow; the first pair of lower labials in 

 contact behind the mental. Two small scales between the second pair of 

 chin-shields. Our specimen has 170 ventrals, a divided anal and 95 pairs 

 of subcaudals. The ventrals and subcaudals are smooth, the scales on 

 the back, the flanks and the tail with many small longitudinal stripes, 

 which give the surface a rough appearance. There is a strong den- 

 ticulated keel on each of the scales. 



