370 GALAPAGOS ARCHIPELAGO. [CHAP. xvn. 



may be questioned whether it is in any other place an aboriginal. 

 The bones of a tortoise at Mauritius, associated with those of the 

 extinct Dodo, have generally been considered as belonging to this 

 tortoise : if this had been so, undoubtedly it must have been there 

 indigenous ; but M. Bibron informs me that he believes that it \vas 

 distinct, as the species now living there certainly is. 



The Arnblyrhynchus, a remarkable genus of lizards, is confined 

 to this archipelago : there are two species, resembling each other 

 in general form, one being terrestrial and the other aquatic. This 

 latter species (A. cristatus) was first characterized by Mr. Bell, who 

 well foresaw, from its short, broad head, and strong claws of equal 

 length, that its habits of life would turn out very peculiar, and 

 different from those of its nearest ally, the Iguana. It is extremely 

 common on all the islands throughout the group, and lives exclu- 

 sively on the rocky sea-beaches, being never found, at least I never 

 saw one, even ten yards in-shore. It is a hideous-looking creature, 

 of a dirty black colour, stupid, and sluggish in its movements. 



Amblyrhynchus cristatus. a, Tooth of, natural size, and likewise magnified. 



The usual length of a full-grown one is about a yard, but there 

 are some even four feet long ; a 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, swimming about; and Captain Collnett, in his 

 Voyage, says, " They go to sea in herds a-fishing, and sun them- 

 selves 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 



