CLASS I. ECHINODERMATA. 
623 
The floor is of sand like the mountain drift 
And tlie pearl-shells spangle the flinty snow : 
From coral rocks the sea-plants lift 
Their boughs when the tides and billows flow. 
The water is calm and still below, 
For the winds and waves are absent there, 
And the sands are bright as the stars that glow 
In the motionless fields of upper air : 
There, with its waving blade of green, 
The sea-flag streams through the silent water, 
And the crimson leaf of the dulse is seen 
To blush like a banner bathed in slaughter : 
There, with a light and easy motion, 
The fan-coral sweeps through the clear deep sea ; 
And the yellow and scarlet tufts of ocean 
Are budding like corn on the upland lea; 
And life, in rare and beautiful forms, 
Is sporting amid those bowers of stone, 
And is safe when the wrathful spirit of storms 
Has made the top of the ocean his own. 
And when the ship from his fury flies. 
When the myriad voices of ocean roar, 
When the wind-god groans in the murky skies. 
And demons are waiting the wreck on shore — 
Then far down in the peaceful sea, 
The purple mullet and gold-fish rove. 
Where the waters murmur tranquilly 
Through the bending twigs of the coral grove." 
The Radiata — so called from tbeir radiate form, and formerly denominated Zoophytes, or Animal 
Plaiits — are divided into five classes : Echinodermata, Siphono2:)hora, Ctenophora, Di&cophora, and 
Polypi. 
star-fish: under side, showing the ambulacral apertures. 
€Ie§§ I. E€lfIN€>l>EIIMATA, 
This term is derived from the Greek eckinos, a spine, and derma, skin ; the animals of this 
class are distinguished for the structure of their skin, which generally presents a somewhat 
leathery consistence. The different species vary greatly in their forms, though they usually 
present a radiate arrangement in their parts. This system is conspicuous in the star-fishes, the 
number five, in the distribution of the rays of these curious species, being more or less traceable in 
the forms of nearly all those belonging to the class. Their organs of motion are similar, consisting of 
a multitude of small feet called ambulacra, which are protruded through a number of perforations 
left for this purpose in their calcareous coverings. The existence of a nervous system in these 
animals is generally admitted by naturalists ; they are all furnished with distinct organs of diges- 
tion and circulation, but it is doubtful if they possess organs of special senses. The sexes are 
