200 ME. G. A. BOULEXGEK OX THE [Feb. 2, 



b. Upper siii-face of head covered with small scales ; no labial pits ; 

 scales keeled 41 . Enygrns carittatus. 



2. Tail not prehensile ; parietal shields very small, or separated from 



each other by an azygous occipital shield. 

 Ventral shields very small ; no azygous occipital. 42. Cylindrophis rvfus. 

 Ventrals well developed ; a large uzygous occipital, in contact with the frontal. 



43. Xeno2)eliis unicolor. 



3. Tail prehensile ; body compressed, covered with uniform, small, 



juxtaposed, rough scales ; no ventral shields. 



44. Ckersydrus granulaius. 



4. Tail not prehensile ; parietal shields large, forming a suture. 



a. luternasal shieldsdistinct from the prsefroutals; head distinct from 



neck. 



a. Pupil round ; scales in 15 to 21 rows, keeled ; anal divided ; 

 ventrals fewer than 200. 



» Scales in 15 rows. 



Scales strongly keeled 45. Tropidonotus sarasinorum. 



Scales feebly keeled 46. Tropidvnotiis celehieus. 



#* Scales in 19 row.s. 

 Two superposed anterior temporals ; 9 upper labials. 



47. Tropid. trianguligerus. 



A single anterior temporal ; 9 upper labials 48. Tropidonotus vittatus. 



Two superposed anterior temporals ; 8 upper labials. 



49. Tropidonotus siibminiatus. 



*## Scales in 21 rows 50. Tropid. chrysargoides. 



/3. Pupil vertical ; scales in 17 or 19 rows. 



Scales in 17 rows ; subeaudals in two rows 51. Lycodon aulicus. 



Scales in 19 rows ; subeaudals single 52. Lycodon stormi. 



y. Pupil round; scales in 13 rows, smooth ; ventrals rounded. 



53. Zarnenis dipsas. 



S. Pupil round ; scales in 21 to 25 rows; ventrals more than 200. 



Scales in 23-25 rows 54. Coluber j'ansctii. 



Scales in 21 rows 55. Coluber erythrurns. 



e. Pupil round ; scales in 13-15 rows; ventrals angiilate laterally, 

 less than 200. 



Scales in 15 rows, vertebrals strongly enlarged... 56. Dendrophis picfus. 

 Scales in 13 rows, vertebrals scarcely enlarged ... 57. Dc7idrelaphis terrificus. 



b. Internasal shields distinct from the prsefrontals ; head small, not 



distinct from neck ; scales in 15 rows. 

 a. Parietal separated from labials by temporals ; a prajocular. 



58. Oligodon waandersii. 

 (3. Pai-ietal in contact with labials. 



Nostril between two nasals ; no prceocular ; pvaefrontal entering the eye. 



59. Agrophis sarasinorum. 

 Nasal single ; a prseocular 60. Rhabdophidium jorsteni. 



c. Internasals fused with the prefrontals ; bead small, not distinct 



from neck ; scales in 13 rows. 

 a. Five upper labials, third and fourth entering the eye. 

 » Anterior chin-shields in contact with the symphysial. 

 t Ventrals 130-187. 



* Frontal three or four times as broad as the supraocular. 



Snout pointed ; rostral as deep as broad 61. Calamaria acutirosiris. 



Snout rounded ; rostral broader than deep 62. Calamaria nucJudis. 



