18 
trilobites, of the transition strata, through the 
extinct crustaceans of the secondary and ter¬ 
tiary formations, and thence onward through¬ 
out existing crustaceans, and the countless 
hosts of living insects. 
“ It appears impossible to resist the con¬ 
clusions as to unity of design in a common 
Author, which are thus attested by such 
cumulative evidences of Creative Intelligence 
and Power; both, as infinitely surpassing the 
most exalted faculties of the human mind, as 
the mechanisms of the natural world, when 
magnified by the highest microscopes, are 
found to transcend the most perfect produc¬ 
tions of human art.” 
We now proceed to the more immediate 
object of this communication, which is to 
describe a portion of the under side of the 
fossil animal, which we have named in our 
monograph caiymene bufo. 
Some time since, my attention was directed 
by Dr. J. J. Cohen, of Baltimore, to a num¬ 
ber of fragments of the head of this species, 
obtained from the vicinity of Berkley, Va., 
