A MONOGRAPH OP THE SPA-SNAKES (HYDROPHIINJE). 191 



absent. Sublinguals, — -two small pairs; both or the posterior only quite separated 

 by scales. Costals, — anteriorly 21 to 25, midbody 21 to 25, posteriorly 19 to 21 ; 

 smooth; the vertebrals may or may not be enlarged. Ventrals, — 137 to 162. 

 Three times or more than three times as broad as the last costal row ; sometimes with 

 a ventral obtuse keel posteriorly. Anal, — divided into two. Colour, — uniform 

 dark brown. 



Habitat. —Pacific Ocean from Celebes to the Royalty Islands. 



Hydreiaps darwiniensis (Boulenger). 

 Hydrelaps darwiniensis, Boulgr. Cat. Hi, 1896, p. 270. 



ABC 

 Fig. 8. — Hydreiaps darwiniensis. After Boulenger. 



I have examined two examples only, both in the British Museum. 



Rostral, — touches four shields; the portion visible above from one-third to one- 

 fourth the internasal suture. Prefrontal s, — touch the second and third supralabials 

 and the eye . Frontal, — touches six shields ; the f ronto-p arietal sutures twice or nearly 

 twice the fronto-prsefrontals. Supraocula r s, — length and breadth about two-thirds 

 that of the frontal. Parietal s, — entire. Nasals, —touch the first and second suprala • 

 bials. Prseocular, — absent. Postoculars, — one. Temporals, — one. Supra- 

 labial s, — 6 ; the third and fourth touch the eye. I n f ra 1 a b i a Is, — the fourth is the 

 largest of the series, and touches three or four scales behind. Marginals, — absent. 

 Sublinguals,— two well developed pairs, in contact with their respective fellows. 

 Costals,— anteriorly 27, midbody 27(28), posteriorly 25 (24) ; smooth, imbricate. 

 Ventrals, — 172 to 173; under three times as broad as the last costal row. Anal, — 

 divided. Colour, — banded with 37 yellowish and black rings, the black rather 

 broader than the yellowish dorsally, rather narrower ventrally. The posterior maxil- 

 lary teeth are grooved. 



Habitat. — Port Darwin. 



Enhydrina valakadyn (Boie). 



"Hoogli pattee " and " valakadyn," Russell, Ind. Serp., 1801, ii, pis. x & xi. 

 Hydrus Valakadyn, Boie, Isis., 1827, p. 554. 

 Hydrophis schistosa, Daudm, Rept., 1803, vii, p. 386. 



Schlegel, Phys. Serp., 1837, ii, P- 500, pi. xviii, figs. 1 to 3. 

 ,, „ Jan, Icon. Gen. 1872, livr. 41, pi. ii, fig. 1. 



,, bengalensis, Gray in Zool. Misc., 1842, p. 62. 

 ,, fasciatus, Jan, loc. cit., livr 41, pi. iii, fig. 2. 

 Pelamis schistosus, Merrem, Tent., 1820, p. 139. 

 Hydrus ,, Cantor, Cat. Mai. Rept., 1847, p. 132. 



