VIPERID^. 



4i: 



Internasals about half the length of the prcefrontals ; the latter 

 entering the eye, between the prasocular and the supraocular ; 

 frontal longer than broad, a little shorter than the parietals : 

 supraocular moderate, nearly half the width of the frontal ; a small 

 loreal ; one praeocular, one postocular, and three or more sub- 

 oculars, excluding the labials from the eye; temporals 2 + 2; 

 upper labials 7, seventh very large ; three pairs of large chin- 

 shields. Scales in 15 rows, dorsals faintly keeled. Ventrals 1G4 ; 

 anal entire; subcaudals 51. Pale brown or reddish brown above, 

 with transverse series of dark brown and white spots; lower parts 

 brownish white, spotted with brown. 



Total length 16 inches ; tail 2-5. 



Hub. Tenasserim. 



Family IX. VIPERID^. 



Facial bones movable ; transpalatine present ; pterygoid ex- 

 tending to mandible ; su|n'atemporal present, attached scale-like to 

 the skull and supporting the cpmdrate ; maxillary short and tliick, 

 movable perpendicularly to the transpalatine, and bearing a pair of 

 large canaliculate fangs. Mandible without coronoid bone, armed 

 with solid tectii. 



jartt 



v]f f_ £ _ ^ 



ar 



a 



Fig. 121. — Skull of Triiiicrcsiiru^ grainineus. 

 A. Upper view. B. Side view. 



ar. Articular. 

 ho. Easioccipital. 

 ca. Ci)liunella auris. 



d. Pentary. 

 eo. Exoffipital. 



/. Frontal. 



m. Maxillary. 

 n. Nasal. 

 p. Parietal. 

 pf. Poison I'ang. 

 2}m. Pra^iiiaxillary. 

 2Jrf. Prjijlrontal. 



pro. Prootic. 



]}f. Pterygoid. 

 pf/. Post frontal. 



q. Quadrate. 



St. Suprateniporal, 



tp. Tran.spalatine. 



2e 



