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Show 466 GALAPAGOS .ARCHIPELAGO. Oct. 1835. different parts of the world. If this. to.rtoise does not originally come from these islands, It IS a remarkable anomaly; inasmuch as nearly all the other land inhabitants seem to have had their birthplace here. Of lizards there are four or five species; two probably belong to the South American genus Leiocephalus, and two to Amblyrhyncus. This remarkable genus was characterized by Mr. Bell,* from a stuffed specimen. sent from Mexico but which I conceive there can be httle doubt originally came through some whaling ship f~om these islands. The two species agree pretty closely m general appearance ; but one is aquatic and the other terrestrial in its habits. Mr. Bell thus concludes his description of Amb. cristatus: "On a comparison of this animal with the true IO'uanas the most striking and important discrepancy is in th0 e form' of the head. Instead of the long, pom• te d, narrow muzzle of those species, we have here a short, obtusely truncated head, not so long as it is broad, the mouth consequently only capable of being opened to a very sh?rt space. These circumstances, 'with the shortness and equality of the toes, and the strength and curvature of the claws, evidently indicate some striking peculiarity in its food and general habits, on which, howev~r, in the a~sence of all certain information, I shall abstam from offermg any conjecture." The following account of these two lizards, will, I think, show with what judgment Mr. Bell foresaw a variation in habit, accompanying change in structure. First for the aquatic kind (Amb. c1·istatus). This lizard ~s extremely common on all the islands throughout the Archipelago. It lives exclusively on the rocky sea-beaches, and is never found, at least I never saw one, even ten yards inshore. It is a hideous-looking creature, of a dirty black colour, stupid and sluggish in its movements. The usual length of a full-grown one is about a yard, but there are some even four feet long : 1 have seen a large one which • Zoological Journal, July, 1835. Oct. 1835. MARINE LIZARD. 467 weighed twenty pounds. On the island of Albemarle they seem to grow to a greater size than on any other. These lizards were occasionally seen some hundred yards from the shore swimming about; and Captain Collnett, in his Voyage, says, "they go out to sea in shoals to fish." With respect to the object, I believe he is mistaken; but the fact stated on such good authority cannot be doubted. When in the water the animal 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. 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, the lizard was quite active. Their limbs and strong claws are admirably adapted for crawling over the rugged and fissured masses of lava, which every where form the coast. In such situations, a group of six or seven of these hideous reptiles may oftentimes be seen on the bJ.ack rocks, a few feet above the surf, basking in the sun with outstretched legs. I opened the stomach of several, and in each case found it largely distended with minced sea-weed, of that kind which grows in thin foliaceous expansions of a bright green or 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 is the case, the object of these animals occasionally going out to sea is explained. The stomach contained nothing but the seaweed. Mr. Bynoe, 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 the certain fact of its having been seen volun- 2 lJ 2 |