174 natural nmrour. 



Snakes and the Homalopsidoe, to enable them to move on land, or 

 at least on mud. They are, in fact, Shore-snakes rather than Sea- 

 snakes, though, like the Fresh-water Snakes, their nostrils are placed 

 high on the snout, and, like the Sea-snakes proper, they have, in 

 addition to this, the ventral region more or less compressed ; and the 

 tail flattened out into an oar, to he used as the single and sculling oar 

 is in a merchantman's dingy. This motion however is not in any 

 Water-snake or in any Land-snake (swimming for the time) confined to 

 the tail. The undulation of the whole body propels it forward, and in 

 some of the most essentially marine species the flat tail, properly so 

 called, is insignificant ; and the abdominal region does most of the 

 propulsion. Snakes, in fact, move in water, as on land, by undulation. 

 Only in the former medium, their best purchase is on their two sides. 

 On shore, it is naturally on the belly. True Sea-snakes, stranded, 

 are even more helpless than fish in a similar position, for the latter do 

 then use their lateral fins on the bottom as legs, and often regain 

 deep water in that way. 



But the Sea-snakes, with their lax bellies and small scales, lie 

 helpless. They wriggle truly, but on one spot, like a rocking- 

 horse ; and they generally remain till a passing man squashes their 

 heads, or a bird of prey carries them off. The Grey Sea-eagle is 

 a great hand at this, and always goes once up and down his beat 

 on the coast, every tide, with a view to tide-falls of the sort. These 

 Sea-snakes without ventral shields, mostly belonging to the genus 

 Hydrophis, are of a great many species, and offer considerable 

 variety in form. I might almost say that amongst them there are- 

 analogues of most venomous Land-snakes. "With a single exception, 

 however, they are of very similar colouring, banded black and white. 



The bands take different shades. In some they almost merge in 

 a general dull grey ; in some the light favouring, you can call them 

 purple and yellow. They are continuous round the body or forked', 

 a single band on the right side meeting two from the left, or those of 

 each side alternate ; but the type is general. 



There are exceptions to it. One is a very widely distributed Snake 

 (Pelamis bicolo)')^ which has several varieties. That commonest here 

 is, when young, velvet black above, on the abdomen golden yellow, and 

 on the flattened tail handsomely mottled black and white above and 

 below. As it ages, apparently, these brilliant colours fade to a dirty 

 olive on the back, and equally dull white below, all over ; but one 

 specimen which I have sent to the Society's Museum seems to 



