192 COLirBKID^. 



9. PRYMNOMIODON. 



Prymnomiodon, Cope, Proc. Ac. Philad. 1860, p. 658 ; Giinth. JRept. 

 Brit. Ind. p. 274 (1864). 



Maxillary teeth, minute posteriorly, becoming muoli longer ante- 

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

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

 trals rounded. Suboaudals in two rows. 



Siam. 



1. Prymnomiodon chalceus. 



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



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

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

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

 postooulars ; eight upper labials, fourth and fifth entering the eye ; 

 posterior chin-shields longer than the anterior. Scales in 19 rows, 

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

 (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 scales 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 with 

 fulvous ; upper labials and prseocular white ; a narrow black post- 

 ocular vitta. 



Length of body 300 mUlim. 



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 



Teopidonotits nicobaeibnsis, 



W. L. Sclater, Journ. As. Soe. Banff. Ix. 1891, p. 241, pi. vi. fig. 5, 



a young Snake from Camorta, ISlicobars, is described and referred 

 with doubt to the genus Tropidonotus, which agrees well in most 

 respects with Prymnomiodon chalceus but for the division of the anal 

 shield and the isodont(?) dentition. It has 162 ventrals and 

 119 suboaudals. 



^- 10. TROPIDONOTUS. . • 



Natrix, part., Zaur. 8yn. Sept. p. 73 (1768). 



Tropidonotus, Ktihl, in Ferussac, Bull. Sc. Nat. ii. 1824, p. 81 : Bote, 



Isis, 1827, p. 518. 

 Tropidonotus, part., Sohleg. Phys. Serp. ii. p. 297 (1837) ; Dum. Sf 



