THE SILURIAN BEACH. 
47 
Of the Echinoderms, the class of Radiates rep- 
resented now by our Star-Fishes and Sea-Urchins, 
we may gather any quantity, though the old-fash- 
ioned forms are very different from the living ones. 
I have dwelt at such length in a former article * 
on the wonderful beauty and variety of the Cri- 
noids, or “ Stone Lilies,” as they have been called, 
from their resemblance to flowers, that I will only 
briefly allude to them here. The subjoined wood- 
cut represents one with a closed cup ; but the 
number of their different pat- 
terns is hardly to be counted, 
and I would invite any one who 
questions the abundant expres- 
sion of life in those days to look 
at some slabs of ancient lime- 
stone in the Zoological Museum 
at Cambridge, where the stems 
of the Crinoids are tangled to- 
gether as thickly as sea-weed 
on the shore. Indeed, some 
of our rock-deposits consist 
chiefly of the fragments of their 
remains. 
The Mollusks were also rep- 
resented then, as now, by their three classes, — 
Acepliala, Gasteropoda, and Cephalopoda. The 
* See Methods of Study in Natural History, Atlantic 
Monthly, No. LVII., July, 1862 . 
