456 CLASS ECHINODERMATA. 
THALASSEMA, Cuwv., 
Have the body oval, or oblong, and the proboscis in the form 
of a plicated lamina, or small spoon, but not forked. But one 
abdominal filament is discoverable. 
We distinguish 
THALASSEMA, (properly so called,) 
Which have only two hooks placed very much in front, and 
the posterior extremity has no sete. (Zhalassema neptunt, 
Gertner, &c.) 
ECHIURUS, 
Whose posterior extremity is furnished with some transverse 
ranges of setz. 
One is known, lumbricus echiurus, Gm., Pall., miscell. Zool. 
xi. 1—6, which inhabits our coasts, on the sandy bottoms. It 
serves as bait to fishermen. 
STERNASPIS, Otto, 
Which, beside the sete of echiurus, have under the anterior 
part, a disk, a little corneous, surrounded with ciliz. (Tha- 
lassema scutatum, Ranz., &c.) 
SECOND CLASS OF ZOOPHYTES. 
INTESTINA, ENTOZOA, Rudolphi, 
Have, for the most part, this peculiarity, that they are unable 
to live, or to propagate, except in the interior of the body of 
other animals. There is almost no animal that does not 
nourish several kinds of them, and those which are observed 
