396 GALAPAGOS ARCHIPELAGO. [chap. xvii. 



large one weighed twenty pounds : on the island of Albemarle 

 they seem to grow to a greater size than elsewhere. Their tails 

 are flattened sideways, and all four feet partially webbed. They 

 are occasionally seen some hundred yards from the shore, swim- 

 ming about ; and Captain Collnett, in his Voyage, says, " They 

 go to sea in herds a-fishing, and sun themselves on the rocks ; and 

 may be called alligators in miniature." It must not, however, 

 be supposed that they live on fish. When in the water this 

 lizard swims with perfect ease and quickness, by a serpentine 

 movement of its body and flattened tail the legs being motion- 

 less and closely collapsed on its sides. A seaman on board sank 

 one, with a heavy weight attached to it, thinking thus to kill it 

 directly ; but when, an hour afterwards, he drew up the line, it 

 was quite active. 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. 



I opened the stomachs of several, and found them largely dis- 

 tended with minced sea-weed (Ulvae), which grows in thin 

 foliaceous expansions of a bright green or a dull red colour. I 

 do not recollect having observed this sea-weed in any quantity 

 on the tidal rocks ; and I have reason to believe it grows at 

 the bottom of the sea, at some little distance from the coast. If 

 such be the case, the object of these animals occasionally going 

 out to sea is explained. The stomach contained nothing but the 

 sea-weed. Mr. JBynoe, however, found a piece of a crab in one ; 

 but this might have got in accidentally, in the same manner as 

 I have seen a caterpillar, in the midst of some lichen, in the 

 paunch of a tortoise. The intestines were large, as in other 

 herbivorous animals. The nature of this lizard's food, as well 

 as the structure of its tail and feet, and the fact of its having 

 been seen voluntarily swimming out at sea, absolutely prove its 

 aquatic habits ; yet there is in this respect one strange anomaly, 

 namely, that when frightened it will not enter the water. Hence 

 it is easy to drive these lizards down to any little point over- 

 hanging the sea, where they will sooner allow a person to catch 

 hold of their tails than jump into the w r ater. They do not seem 



