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SUPPLEMENT 
seems probable that it can proceed to form another. Pallas, 
in fact, informs us, that when it is very much annoyed there, 
it will issue forth spontaneously, and make its escape by 
a vermicular kind of movement. 
The Amphitrite is a genus of marine worms, whose 
character consists in having the head furnished with two 
pieces of a metallic lustre, and similar in form to combs. 
These animals, for the most part, inhabit tubes, which they 
form by agglutinating small grains of sand or fragments of 
shells, and which are sometimes fixed, and sometimes free, 
according to the species. The body of the amphitrite is in 
the form of an elongated cone, and is ordinarily terminated by 
a long and tubular tail. The rings which compose the body 
support all, or in part, on each side, a fasciculus of some still 
seta), which the animal employs for motion. There are also 
at each of these rings some fleshy filaments. The gills of the 
amphitrite are attached to the anterior part of the body only, 
as happens with all the w T orms that inhabit tubes, because 
gills attached to the other parts of the body, which are sunk 
in the tube, would be useless for respiration ; these gills are 
in the form of a plume of leathers, and their greatest number 
is four pair. The head of the amphitrite is as it were trun- 
cated : around its mouth are filaments, more or less numerous, 
which serve as tentacula; the two brilliant combs are placed 
underneath. It is probable that the animal makes use of 
them to attract towards it the bodies which are to become its 
prey, or the grains of sand which it desires to attach to its 
tube. 
The amphitrites have, for the most part, a skin so fine, and 
so transparent, that all their interior is perceptible through it ; 
this interior generally consists only in an intestinal canal, as 
thin as the skin itself, and almost always filled with sand. 
There are, however, some species which have a muscular 
