352 OPHIDIA. 



to the tip of the tail ; a series of small ovate black spots, indistinctly edged with whitish, 

 along each side of the trunk, disappearing posteriorly ; tail coloured like body, without black 

 rings. In old examples the black dorsal stripe and the black lateral spots disappear, and 

 only the whitish edges of the latter remain, forming indistinct longitudinal lines. 



Vertical shield elongate. Upper labials seven ; temporals 1 + 1, the anterior twice the size 

 of the posterior. Ventrals 232-247 ; anal entire, in one specimen bifid ; subcaudals 33-42. 



I have examined three specimens of this species, one of which was sent by Captain 

 R. H. Beddome from the Nilgherries ; the largest is 4 feet long, the tail measuring 5 inches. 

 We have given (F) two views of its head, and one of a portion of the body, to show its 

 coloration : for comparison we have added (F') a figure of a portion of the body of a 

 younger example. 



FAMILY OF SEA ^^AKES—HYDROPHW.^. 



Body subcyllndrlcal anteriorly, more or less compressed posteriorly ; tail 

 strongly compressed, elevated, ])addle-shaped. Head-shields generally ab- 

 normal ; loreal none. Nostrils situated on the upper side of the head, 

 except in Platurus. Eye small, with round pupil. The venom-fang small, 

 grooved in front, and with a canal in its interior terminating in a short slit. 



The Sea-snakes are inhabitants of the tropical parts of the Indian and Pacific Oceans, 

 extending from the coast of Madagascar to the Isthmus of Panama ; they are most numerous 

 in the East Indian Archipelago and in the seas between Southern China and North Australia, 

 being represented on the outskirts of the geographical range we have mentioned by only one 

 species, and that the most common, viz. Pelamis bicolor. They pass their whole life in the 

 water (with the exception perhaps of Platurus), and soon die when brought on shore. 



The most striking feature in the organization of the Sea-snakes is their elevated and com- 

 pressed tail, the processes of the caudal vertebrae being much prolonged and styliform. The 

 hind part of the body, and sometimes forwards to beyond the middle of its length, is also 

 compressed, and the belly forms a more or less sharp ridge. The ventral shields would be of 

 no use to snakes moving through a fluid, and not over a rough hard surface, and therefore 

 they are either only rudimentary or entirely absent. The genus Platurus, however, is a most 

 remarkable exception in having ordinary ventral shields ; and this circumstance, together 

 with the lateral position of its nostrils, induce me to believe that these serpents frequently go 

 on shore, sporting or hunting over marshy ground. In many Sea-snakes the hind part of the 

 body is curved and prehensile, so that they are enabled to secure a hold by twisting this part 

 of the body round corals, seaweeds, or any other projecting object. Their tail answers all 

 the purposes of the same organ in a fish, and their motions in the water are almost as rapid 

 as they are uncertain and awkward when removed out of their proper element. Their nostrils 



