148, DIPSADOMORPHTJS. 61 



PrsBoculax usually in contaot with or 



narrowly separated from the frontal; 



suboaudals 90-125 5. eeylonensis, p. 66. 



Prjeocular not reaching the frontal ; 



suboaudals 87-103 6. fuscus, p. 67. 



h. Posterior chin-shields not larger than the anterior. 



a. Scales in 19 rows ; ventral's 240-260 ; suboaudals 

 110-124 7. pulverukntus, p. 68. 



/3. Scales in 21 or 23 rows. 



* Suboaudals 89-110. 



Scales in 21 rows, vertebrals feebly 



enlarged ; ventrals 231-248 8. multifasciatus, p. 69. 



Scales in 23 rows, vertebrals feebly 



enlarged ; ventrals 241 9. dightonii, p. 69. 



Scales in 21 (rarely 23) rows, verte- 

 brals more or less strongly enlarged; 

 ventrals 209-239 10. dendropUlus, p. 70. 



** Suboaudals 124-144 ; scales in 21 rows. 



Ventrals 237-252; suboaudals 124- 



133 11. oyaneus, p. 72. 



Ventrals 240-263 ; suboaudals 143- 



144 12. nigriceps, p. 72; 



B. Snout as long as the eye. 



1. Scales in 21 tows ; ventrals 243-266 ; suboaudals 140-166. 



13. jasjpideus, p. 73. 



2. Scales in 19 rows. 



Ventrals 220 ; suboaudals 99 ; three 



prseoculars 14. barnesii, p. 73. 



Ventrals 250-276 ; suboaudals 114- 



163 ; posterior chin-shields not 



much smaller than the anterior . . 15, drapiezii, p, 74. 

 Ventrals 254-258 ; suboaudals 126- 



135 ; anterior chin-shields nearly 



thrice as large as the posterior .... 16. angulatm, p. 75, 



11. Anterior palatine teeth strongly enlarged. 



A. Posterior obin-shields larger than the anterior ; scales in 19- 

 to 23 (rarely 25) rows. 



Scales in 19-23 rows ; ventrals 217- 

 270 ; anal entire ; suboaudals 103- 

 125 ; one praeocular, extending to 

 upper surface of head 17. irregularis, p. 75. 



