HATTERIA AND THE LIZARDS 



saurs, seem to have had smooth scaleless skins, but no 

 living reptile is without this tesselated armature. The 

 existing reptiles are to be divided into five orders, 

 but their numbers to-day are much below their numbers 

 in past times. The reptilia are clearly a waning race as 

 a whole, though of the existing orders most are more 

 numerous now than they ever have been so far as the 

 geological evidence at our disposal enables as to say. 

 As to their numbers to-day, Dr. Gadow asserts that 

 there are about 3,500, so that there are more reptiles 

 than mammals, but considerably fewer than there are 

 fish and birds ; for of the latter we know some 10,000, 

 and of fishes some 8,000, while there are something like 

 2,700 mammals and about 1,000 amphibians. The 

 enormous majority of living reptiles belong to the 

 groups of lizards, snakes, and tortoises. There are 

 but few crocodiles, and Hatteria is the only living 

 example of its own group. 



LIZARDS : THE ORDER LACERTILIA 



The only other reptiles with which the lizards could 

 be possibly confounded are the crocodiles, snakes, and 

 the New Zealand Hatteria, which is the sole living 

 representative of an otherwise extinct order, Rhyncho- 

 cephalia. The turtles and tortoises are so distinct that 

 there is no danger of confusion for the most ignorant 

 of Natural History. From the crocodile tribe the 

 lizards are to be distinguished by a variety of characters, 

 which are, however, deep seated, and thus not easily 

 appreciable to one examining the animals in a menagerie. 

 As to purely external characters, it is most difficult 

 to draw a line. In the crocodile tribe the nostrils are 

 very plainly on the upper surface of the snout and 

 protrude somewhat, which is of course in relation to 

 the aquatic life of these creatures. The vent is a 

 longitudinal orifice and not a transverse one as in 



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