02 
SYSTEM OF NATURE. 
that, together with the other Enaliosaurians, the really 
structural and osteological approaches exhibited are to the 
scaly lizards generally. The common and vague compa¬ 
rison to crocodiles and lizards seems to me to arise from 
a careless blending of these two widely diverse groups; 
and the similarity to whales arises, as in marsupials and 
birds, from the necessity for each class to possess a natant 
or ichthyoid division.. With regard to the carapaciform 
covering, supposing that such a covering really existed, 
its dissimilarity to that of tortoises is manifested in the 
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fact that the ribs of the Enaliosaurians are always free and 
distinct. 
From these remarks, cautiously compiled, so as to avoid 
all hypotheses, it seems — 1st. That the crocodiles more 
closely approach the Testudinata than the Squamata. 
2ndly. That the Enaliosaurians more nearly approach the 
Squamata than any other group, the points of resemblance 
to certain lizards being decidedly more important than 
those so often cited to crocodiles and whales. 3rdly. 
That the result is the formation of two classes, the first 
nearly coinciding with the Cataphracta of Latreille, distin¬ 
guished by their bony armour, consisting—1st, of the 
Testudinata certainly; 2ndly, of the Crocodilia, with some 
degree of doubt; and 3rdly, of the Amphisbaenia, with a 
greater degree of doubt: the second class, distinguished 
by the absence of bony armour, would contain— 1st, the 
Squamata of Merrem certainly; 2ndly, the Amphibia of 
Cuvier, with a degree of doubt; and 3rdly, the Enalio- 
sauri of Conybeare, also with doubt. 
When we consider this double group of amphibious 
animals as it once was, — when we compare the existent 
Iguana with the Iguanodon of former days, half as long as 
