XIII PHYLUM CHORD ATA 369 



completely submerged with the exception of the extremity of the 

 snout bearing the nostiils, they are often able by tlie suddenness 

 and swiftness of their onset to seize the most watchful and timid 

 animals. In the majority of cases the greater part, and in some 

 the whole, of their food consists of Fishes ; but all the larger and 

 more powerful kinds prey also on Birds and Mammals of all kinds, 

 which they seize unawares when they come down to drink or 

 attempt to cross the stream. On land their movements are com- 

 paratively slow and awkward, and they are correspondingly more 

 timid and helpless. 



The Crocodilia, as already mentioned, are all oviparous, and the 

 eggs, as large in some species as those of a Goose, are brought 

 forth in great numbers (sometimes 100 or more), and either buried 

 in the sand, or deposited in rough nests. 



Geographical Distribution. — The order Lacertilia, the most 

 numerous of the orders of Reptiles living at the present day, is of 

 very wide distribution, occurring in all parts of the eaith's surface 

 ■ except the circumpolar regions ; but some of its larger sections are 

 of limited range. The Geckos are numerous in all warm countries, 

 their headquarters being Australia and the Oriental region. The 

 snake-like Pygopidse are entirely confined to the Australian 

 region. The Agamidje (a family which includes the Flying 

 Lizards besides many others) are most abundantly represented in 

 the Australian region, though extending to other regions of the 

 Old World, except New Zealand and Madagascar. Of the Iguanas 

 two genera occur in Madagascar and one in the Friendly Islands ; 

 all the other members of this group, which is a large one, are 

 confined to America. Three families occur exclusively in America 

 — the Xenosauridse, the Tej idee, and the Helodermidffi, or poisonous 

 Lizards. The Zonuridse or Girdle-tailed Lizards are confined to 

 Africa and Madagascar. The Anguidse or Blind-worm Lizards are 

 mostly American, but are represented in Europe and Asia. The 

 family of the Monitors is distributed in Africa, Southern Asia, 

 Oceania, and the Australian region. The Snake-like Amphis- 

 bsenians are most, numerous in America, but are well represented 

 in Africa, and occur also in the Mediterranean area. The Lacer- 

 tidse are most abundant in Africa, but occur in Europe and Asia. 

 The family of the Skinks (Scincidse) is of world-wide range, but is 

 most abundant in Australia, Oceania, the Oriental region and 

 Africa. Sphenodon is confined to the Ne*w Zealand region, and at 

 the present day only occurs on certain small islands off the N.E. 

 coast and in Cook's Straits. The Chamasleons are most abundant 

 in Africa and Madagascar, but there are representatives in various 

 other parts of the Old World ; they do not occur in the Australian, 

 New Zealand, or Polynesian regions, and are only represented in 

 Europe by one species which occurs in Andalusia. 



Chelonia arc widely distributed over the surface of the earth, by 



