147 
TODUS. 
The genus Todus evidently succeeds the last. As 
it is one of them which are typical of this sub- 
family, we should expect to find it more numerous 
in species and more diversified in forms; and such we 
discovered to he the case. Unlike the three aberrant 
divisions we have just quitted, the one before us 
presents us, for the first time in this family, with a 
complete and perfect circle, where scarcely a link 
is missing; and where we have, in consequence, 
the five types of nature fully and perfectly demon- 
strated. Hitherto we have been barely able, with 
much difficulty, and some latent doubts, to make 
out the prominent types of the divisions just gone 
through ; not so much from the absolute relations 
which they bear to each other by intervening spe- 
cies, as by comparing our distribution of the order 
of their succession with that of other and more 
perfect circles, whose validity has been long esta- 
blished. But in the todies we can proceed with 
more confidence ; for if, amidst so much variation, 
we can yet establish the same uniformity, and add 
another instance in corroboration of those general 
laws elsewhere promulgated, additional confidence 
