230 



LYELL'S ELEMENTS OF GEOLOGY. 



Living Marine Saurian. 



ground, swarming everywhere on the land, having a round tail, 

 and a mouth somewhat resembling in form that of the tortoise. 

 The other is aquatic, and has its tail flattened laterally for swim- 

 ming (see Fig. 229.). " This marine saurian," says Mr. Darwin, 

 " is extremely common on all the islands throughout the archi- 

 pelago. It lives exclusively on the rocky sea-beaches, and I 

 never saw one even ten yards inshore. The usual length is 

 about a yard, but there are some even four feet long. It is of a 

 dirty black colour, sluggish in its movements on the land; but, 

 when in the water, it swims with perfect ease and quickness by 

 a serpentine movement of its body and flattened tail, the legs 

 during this time being motionless, and closely collapsed on its 

 sides. Their limbs and strong claws are admirably adapted for 

 crawling over the rugged and fissured masses of lava which 

 everywhere form the coast. In such situations a group of six 

 or seven of these hideous reptiles may oftentimes be seen on the 

 black rocks, a few feet above the surf, basking in the sun with 

 outstretched legs. Their stomachs, on being opened, were found 

 to be largely distended with minced sea-weed, of a kind which 

 grows at the bottom of the sea, at some little distance from the 

 coast. To obtain this, the lizards are seen occasionally going 

 out to sea in shoals. One of these animals was sunk in salt 

 water, from the ship, with a heavy weight attached to it, and 

 drawn up again after an hour ; it was quite active and unharmed. 

 It is not yet known by the inhabitants where this animal lays 

 its eggs ; a singular fact, considering its abundance, and that 

 the natives are well acquainted with the eggs of the terrestrial 

 Amhlyrhynclms, which last is also herbivorous, although feed- 

 ing on a very different kind of vegetation."* 



In those deposits now forming by the sediment washed away 

 from the wasting shores of the Galapagos islands, the remains 

 of saurians, both of the land and sea, as well as of chelonians 

 and fish, may be mingled with marine shells without any bones 

 of land quadrupeds or batrachian reptiles ; yet even here we 

 should expect the remains of marine mammalia to be imbedded 

 in the new strata, for there are seals, besides several kinds of 

 cetacea, on the Galapagian shores ; and, in this respect, the 

 parallel between the modern fauna, above described, and the 

 ancient one of the lias, would not hold good. 



Sudden destruction of saurians, <Sfc. — It has been remarked, 

 and truly, that many of the fish and saurians, found fossil in the 

 lias, must have met with sudden death and immediate burial ; and 



* Darwin's Journal, chap. xix. 



