SIMOTES TMNOTATUS. 219 



labials; posterior chin-shields small, scale-like. Ventral shields 163-164; anal entire; 

 subcaudals 42-45. Ventral shields slightly bent upwards on the side of the body. Yellowisli 

 olive above : fronto-labial band distinct ; the oblique band on the side of the occiput does 

 not meet its fellow on the crown of the head, but is confluent with a broad angular nuchal 

 band. Numerous scales on the back are edged with black, the black edges producing nume- 

 rous irregular narrow transverse lines and less numerous broader cross bars, the latter about 

 fourteen in number. A broad lighter band runs along each side of the back ; tail with a 

 median whitish longitudinal band. Lower parts pure white. 



We have received two specimens from Pachebone, through M. Mouhot ; they are 19 inches 

 long, the tail measuring 3 inches. Two views of the head are given on Plate XX., of the 

 natural size. 



SiMOTES COCHINCHINENSIS. (Plate XX. fig. C.) 



Scales in twenty-one rows. Occipitals rounded behind ; loreal distinct ; two prseorbitals, 

 the lower of which is much smaller than the upper ; two postorbitals ; eight upper labials, 

 the fourth and fifth of which form the lower part of the orbit; temporals 2+2. Anterior 

 chin-shields nearly twice as long as broad, in contact with four lower labials ; posterior chin- 

 shields small, scale-like. Ventral shields 216 ; anal enth-e ; subcaudals 47. Ventral shields 

 with an obtuse keel on each side. Greyish olive, with twelve black cross bands on the 

 trunk, and three on the tail ; each of these bands is two scales broad, and formed by two 

 square spots on the back and by a smaller spot on each side ; these spots are confluent. 

 Markings of the head deep black ; the nuchal blotch emits a process forAvards, extending to 

 the vertical and separating the oblique bands which descend behind each angle of the mouth. 

 Lower parts pure white. 



We have seen only one young specimen of this species, which was found by M. Mouhot in 

 the Lao Mountains ; it is 7 inches long, the tail measuring 1 inch. 



SiMOTES TEINOTATUS. 



Simotes trinotatus, Dum. ^ Bibr. vii. p. 631. 



Xenodon piirpurascens. Cantor, Mai, Rept. p. 67 (uot Schleg.). 



Scales in twenty-one rows. Loreal distinct ; two prae- and two (three) post-orbitals ; eight 

 upper labials, the fourth and fifth of which enter the orbit. Ventral shields 183-189, Avith 

 an obtuse lateral keel; anal entire; subcaudals 49-51. Yellowish brown, with a triple 

 series of darker, black-edged spots : the lateral spots have a curved upper black edge, the 

 convexity of which is turned upwards, and each is united with the corresponding spot of the 

 other side by an intermediate subhexagonal spot. The markings on the head are indistinct ; 



2 f2 



