354 OPHIDIA. 



object it wants to strike. The tongue is short, and the sheath in which it lies concealed 

 opens near to the front margin of the lower jaw; scarcely more than the two terminating 

 points are exserted from the mouth when the animal is in the water. The mouth shuts in 

 a somewhat different way from that in other snakes, the middle of the rostral shield being 

 produced downwards into a small lobule which prevents the water from entering the mouth ; 

 this lobe is most developed in Enhydrina. There is generally a small notch on each side of 

 the lobule for the passage of the two points of the tongue. Cantor says that when the snake 

 is out of the water and blinded by the light, it freely makes use of its tongue as a feeler. 



The food of the Sea-snakes consists entirely of small fish ; I have found all kinds of fish in 

 their stomach — among them species with very strong spines {Apogon, Siluroids) ; as all these 

 animals are killed by the poison of the snake before they are swallowed, and as their muscles 

 are perfectly relaxed, their armature is harmless to the snake, which commences to swallow 

 its prey from the head, and depresses the spines as deglutition proceeds. There cannot be 

 the slightest doubt that the Sea-snakes belong to the most poisonous species of the whole 

 order. Russell and Cantor * have ascertained it by direct observation : tortoises, other snakes, 

 and fish died from their bite in less than an hour, and a man succumbed after four hours. 

 Accidents are rarely caused by them, because they are extremely shy and swim away on the 

 least alarm ; but when surprised in the submarine cavities forming their natural retreats, they 

 will, like any other poisonous terrestrial snake, dart at a pole ; or, when out of the water, 

 they attempt to bite every object near them, even turning round to wound theii- own bodies 

 ( Cantor). They cannot endure captivity, dying in the course of two or three days even when 

 kept in capacious tanks. 



The males may be easily distinguished from the females by a distinct swelling on each side 

 of the tail, extencUng from the root to, or beyond, the middle of its length ; sometimes the 

 whole tail is thickened, and such specimens may be taken for distinct species. All the 

 species are viviparous, bringing forth, without leaving the sea, from four to nine young ones. 

 The young are more brightly coloured than the adult, the faint cross bands of the latter 

 being complete black rings in the former ; the tail also of the young is comparatively thicker 

 and less compressed than in the adult. That they live to a great age I infer from the cir- 

 cumstance that we find relatively very large examples of almost every species, but that such 

 examples are very scarce. Now, as they have very formidable and very numerous enemies in 

 the sea-eagles {HaUaetus), in the sharks, and other lai'ge raptatorial fishes, it appears to me 

 to be a just conclusion, that, if Sea-snakes of large dimensions were more numerous than 

 they are, they would, in spite of those enemies, arrive at that size in a shorter period than 

 that which we assume as necessary for their growth. The greatest size, however, to which 

 some species attain, according to positive observation, is about 12 feet, and, therefore, far 

 short of the statements as to the length of the so-called " Sea-serpents." The largest example 

 I have seen measured only 8 feet. 



There is no other group of reptiles the species of which are so little known, and the 

 synonymy of which is so confused, as that of the Sea-serpents. All the preceding authors, 

 with the exception of Gray, have worked at them with the idea that the species were less 

 numerous than they in reality are ; thus confounding forms which had been previously dis- 

 tinguished, though imperfectly characterized. Having had the gi-eat advantage of examining 



* Trans. Zool. Soc. ii. p. 303. 



