SNAKES. 59 



2. The Ringed Sea-Snake . Hydrus aiiDulatus. 

 Yellow, with irregular hlack rings ; hinder ocular 2, and an ob- 

 long inferior ocular between the eyes and labial shields. 



a. Adult. Singapore. From Mr. Gardener's collection. 



c. Ventral shields broad, six-sided, keeled in the middle, with sides 

 folded together ; body covered ivith smooth polished scales. 



10. TOMOGASTEE. 



Tomogaster, Dum. ^ Bib. MSS. Voy. Pol. Sud. Oph. f. 6, 

 not described. 



Head rather small, regularly shielded ; crown flattened : rostral 

 broad, six-sided ; nasal large, superior, close ; frontals one pair, 

 transverse, truncated in front, with two angles behind ; vertebral 

 and occipital well developed ; superciliary one over each eye large : 

 one large anterior and two posterior oculars : labial shields square, 

 the fourth upper under the eye : temple shielded : chin shields two 

 pairs : body subcylindrical, slightly angular ; belly keeled, especially 

 behind: scales ovate, smooth, thin, rather polished : ventral shield 

 broad, six-sided, keeled, entire : tail compressed : scales smooth, 

 upper and lower series keeled and folded together. The scales have 

 more the appearance of Hydrina, while those of Stephanohydra 

 resemble the scales oi Elaps and other terrestrial snakes. 



1. The Tomogaster. Tomogaster Evdouxii, Bibron, MSS.. 

 Voy. Pol. Sud. Ophid. t. 6. 



Slate-coloured, with cross-bands of roundish white spots united, 

 forming pale triangular spots on the lower part of the sides ; belly 

 whitish ; head black, not spotted ; neck blackish. 



a. In spirits. Indian Ocean. From the Paris collection. 

 " Tomogaster Eydouxii." 



11. Stephanohydra. 



Head rather large, depressed, rounded in front ; head-shields 

 numerous, unequal, smooth, polished ; parietal largest ; supra-or- 

 bital 3-3 ; front small, hinder largest ; nasal large, superior ; ante- 

 rior ocular 1 ; posterior 3, unequal : labial shields large, high, the 

 middle ones reaching to the lower edge of the orbit : rostral square, 

 large, convex; inferior rostral small, triangular, with a rounded 

 notch above ; temple and throat covered with six-sided imbricate 



