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CHAPTER Xx. 
THE ACEPHALOUS MOLLUSKS. 
ALTHOUGH the gregarious mollusks are veritable members of 
the sub-kingdom we are considering, yet they cannot be said 
to be its fair representatives, seeing they have not an individual 
and independent life. Hence the solitary mollusks are said to be 
true mollusks. 
The Acephalas being found at the bottom of the class, we 
shall consider them first. Some are naked, some have shells. 
The naked members of the class are generally adherent to the 
fuci, to the shells of better protected mollusks, or to the rocks. 
They have little, if any, power of locomotion. The solitary 
Ascidia, for example, is condemned to an immovable life—once 
fixed, it never again attempts to leave its position, and lives and 
dies attached to the same spot. 
One of the members of the ascidian family—the Azchus, which 
cannot boast of an elegant appearance—is found in the neighbour- 
hood of Cette, and is sold in the market for food: Its thick 
leathery skin having been stripped off, and its viscera taken out, 
the remainder is eaten. At first the taste is saltish ; but when 
swallowed, a sharp, peppery taste remains in the mouth. 
These mollusks are furnished with two openings, the margins 
of which are ciliated, and if the animal be pressed in the least, it 
ejects water from them with considerable force. 
The ascidiz have no hands nor yet lips wherewith to seize their 
prey; their mouth is placed very favourably, at the lower part of 
the sac, but not at the very extremity. Nature has not forgotten 
to provide the animal with the power of nourishing itself. The 
inner surface of the visceral cavity is furnished profusely with 
vibratory cils, which cause the water to pass in strong currents 
towards the buccal orifice. When observed under the microscope, 
