ORDER ACALEPHA. 431 
But a single genus is known. 
LIGuLaA, Bloch., 
Are, of all the intestina, those which appear to be the most 
simply organized. Their body resembles along riband. It 
is flat, obtuse in front, marked with a longitudinal stria, and 
finely striated cross-wise. No external organ is distinguish- 
able, and in the interior, nothing is seen but eggs, variously 
distributed through the length of the parenchyma. 
They live in the abdomen of some birds, and more particu- 
larly in that of several fresh-water fish, whose intestines they 
envelope and press to such a degree, as to cause them to 
perish. At certain periods, they even pierce their abdomen 
to get out. 
There is one in the bream. Lig. abdominalis, Gm. L. cin- 
gulum, Rud. Geetz. xvi. 4—6, which attains even to the length 
of five feet. These worms, in some parts of Italy, are consi- 
dered as an agreeable food. 
THE THIRD CLASS OF THE ZOOPHYTES. 
ACALEPHE, Vulg. SEA-NETTLES, 
Comprehend zoophytes which swim in the waters of the 
sea, and in the organization of which some vessels are per- 
ceived which, in truth, are most frequently only productions 
of the intestines, hollowed in the parenchyma of the body. 
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