188 Barrande— Origin of Paleozoic Species. 
the contrary, wherever we observe the first appearance of a 
type, the conformation of the shell offers to us all the characters 
which distinguish it from other types of this order. No coun- 
try seems to us to have been more favorable than Bohemia for 
the preservation of transition forms between the 20 types which 
it ee: for many of them are represented by myriads of 
individuals, among which we do not discover any intermediate 
form. Of certain species, * * we have been able to collect 
the of econ van intermediate forms between the types invari- 
i 
ocerata noted in our studies upon the evolution of the 
Cephalopods, as offering ideally an intermediate type between 
