192 COLtJBKIDiE. 



9. PRYMNOMIODON. 



Prymnomiodon, Cope, Proc. Ac. Philad. I860, p. 558 ; Giinth. Rept. 

 Brit. Ind. p. 274 (1864). 



Maxillary teeth minute posteriorly, becoming much longer ante- 

 riorly. Head moderately distinct from neck. Eye rather large, 

 with round pupil. Body slender; scales, keeled, in 19 rows; ven- 

 trals rounded. Subcaudals in two rows. 



Siam. 



1. Prymnomiodon chalceus. 



Prymnomiodon chalceus, Cope, I.e.; Giinth. I.e. 



Snout rather narrow. Eostral nearly as deep as broad : nostril 

 between two nasals, which are equal in size ; frontal rather large ; 

 loreal trapezoid ; one praeocular, not reaching the frontal ; three 

 postoculars ; eight upper labials, ff)urth and fifth entering the eye ; 

 pos^eiior chin-shields longer than the anterior. Scales in 19 rows, 

 elongate, all keeled. Ventrals 152 ; anal entire ; subcaudals — ? 

 (tail mutilated). Olivaceous above, shading into leek-green upon 

 the flanks, and greenish white upon the belly ; a vertebral stripe of 

 light green bordered with black extends from the parietal shields to 

 the origin of the tail, involving one row of scales and two halves; 

 another narrower and paler stripe extends from the third and fourth 

 rows of settles upon each side from the neck to the origin of the 

 tail ; this stripe is bounded above by an interrupted narrow black 

 border ; temporal region bright green, shields of head tinged wi ^h 

 fulvous ; i.pper labials and prseocular white ; a narrow black po3t- 

 ocular vitta. 



Length of body 300 millim. 



Siam. 



Judging from the description, this Snake appears to resemble 

 closely the American Tropidonotus saurita, from which, however, the 

 dentition distinguishes it. 



Under the name of 



Teopidonotus nicobariensis, 

 W. L. Sclater, Journ. As, Sac. Bevg. Ix. 1891, p. 241, pi. vi. fig. 5, 



a young Snake from Camorta, N'cobars, is described and referred 

 with doubt to the genua Tropidono iis, which agrees well in most 

 respects with Prymnomiodon chalceus but for the division of the anal 

 shield and the- isodont(?) dentition. It has 162 ventra-ls and 

 119 subcaudals. 



■ / ■■ 

 10. TROPIDONOTUS. 



Natrix, part,, Laur. Syn. Rept. p. 73 (1768). 



Tropidouotus, Kidil, in Ferussac, Bull. Sc. Nat. ii. 1824, p. 81 ; Bote, 



Ms, 1827, p. 518. 

 Tropidouotus, part., Schleg. Phys. Serp. ii. p. 297 (1837) ; Dum. ^ 



