58 
THE SILURIAN BEACH. 
prominent anterior shield, unite characters ot 
Worms and Crustacea. 
These early types seem to sketch in broad, gen- 
eral characters the Creative purpose, and to in- 
clude in the first average expression of the plan 
all its structural possibilities. The Crinoid forms 
include the thought of the modern Star-Fishes 
and Sea-Urchins ; the simple chambered shells 
of the Silurian anticipate the more complicated 
structure of the later ones ; the Trilobites give 
the most comprehensive expression of the Articu- 
late type ; while the early Fishes not only proph- 
esy the Reptiles which are to come, but also hint 
at Birds and even at Mammalia by their embry- 
onic development and their mode of reproduc- 
tion. 
Looked at from this point of view, the animal 
world is an intellectual Creation, complete in all 
its parts, and coherent throughout ; and when we 
find, that, although these ancient types have be- 
come obsolete and been replaced by modern ones, 
yet there are always a few old-fashioned individ- 
uals, left behind, as it were, to give the key to 
the history of their race, as the Gar-Pike, for in- 
stance, to explain the ancient Fishes, the Mille- 
pore to explain the old Acalephian Corals, the 
Nautilus to be the modern exponent of the Am- 
monites and Orthoceratites of past times, we can- 
not avoid the impression that this Creative work 
