Ch. XXL] LIAS — SAUKIANS. 325 



as the turtle, frequenting the ocean, so there may have been formerly 

 some saurians proper to salt, others to fresh water. The common croco- 

 dile of the Ganges is well known to frequent equally that river and the 

 brackish and salt water near its mouth ; and crocodiles are said in lika 

 manner to be abundant both in the rivers of the Isla de Pinos (or Isle of 

 Pines), south of Cuba, and in the open sea round the coast. More re- 

 cently a saurian has been discovered of aquatic habits and exclusively 

 marine. This creature was found in the Galapagos Islands, during the 

 visit of H. M. S. Beagle to that archipelago, in 1835, and its habits 

 were then observed by Mr. Darwin. The islands alluded to are situated 

 under the equator, nearly 600 miles to ihe westward of the coast of 

 South America. They are volcanic, some of them being 3000 or 4000 

 feet high ; and one of them, Albemarle Island, 75 miles long. The 

 climate is mild ; very little rain falls ; and, in the whole archipelago, 

 there is only one rill of fresh water that reaches the coast. The soil is 

 for the most part dry and harsh, and the vegetation scanty. The b:.<rds, 

 reptiles, plants, and insects are, with very few exceptions, of species 

 found nowhere else in the world, although all partake, in their general 

 form, of a South American type. Of the mammalia, says Mr. Darwin, 

 one species alone appears to be indigenous, namely, a large and peculiar 

 kind of mouse ; but the number of lizards, tortoises, and snakes is so 

 great, that it may be called a land of reptiles. The variety, indeed, of 

 species is small ; but the individuals of each are in wonderful abundance. 

 There is a turtle, a large tortoise (Testudo Indicus), four lizards, and 

 about the same number of snakes, but no frogs or toads. Two of the 

 lizards belong to the family Iguanidce of Bell, and to a peculiar genus 

 {Amblyrhynchus) established by that naturalist, and so named from 

 their obtusely truncated head and short snout.* Of these lizards one 

 is terrestrial in its habits, and burrows in the ground, swarming every- 

 where on the land, having a round tail, and a mouth somewhat resem- 

 bling in form that of the tortoise. The other is aquatic, and has its tail 

 flattened laterally for swimming (see fig. 418.) "This marine saurian," 



Fig. 41 s. 



Amblyrhynchus cristatus, Bell. Length varying from 3 to 4 feet. The only existing marine 

 lizard now known. 



a. Tooth, natural size and magnified. 

 * AfiSAvj, amblys, blunt ; and frvyxos, rhynchus, snout. 



