1 64 TODUS. 



and the tarsi, axe three of the primary distinctions 

 of the Fissirostres and the Natatores. While the 

 remarkably long legs of T. Platydrcm* might lead 

 us to believe it was the representation of the gralhi- 

 torial birds, but for its tail, which is twice the or- 

 dinary length, and although unusually broad, yet 

 the ends are pointed. The formation, therefore, of 

 this member, stamps the bird at orioe as a rasorial 

 type ; both these orders, in fact, have generally 

 long legs, but it is only the Rasores that have either 

 oread tails or pointed feathers. We may, therefore, 

 fairly conclude, that the species of Todus which 

 represents the Grallatores has not yet been disco- 

 vered, or rather that it has not yet fallen under our 

 observation. 



The law of representation, although universal, is 

 yet so simple, that if it is successfully demonstrated 

 in any one group, it becomes equally established in 

 all ; because all must be referred to one general 

 test, that is, to the primary types of nature. This 

 has been so frequently exemplified in our treatise 

 upon birds, and in that upon quadrupeds, that it 

 becomes unnecessary to compare our present group 

 with all others of the class or order to which it be- 

 longs; unless, indeed, there are some points of 

 structure to be elicited which cannot be explained 

 by a single analogical comparison. Nevertheless, 

 the views here taken of the particular group before 



* The only specimen of this species I have yet seen is iu 

 the Paris Museum. 



