FIRST ORDER OF ANNELIDA. 
THE TUBICOL.E*. 
Some form a calcareous homogeneous tube, resulting probably 
from their transudation, like the shell of the mollusca, to which, 
however, they do not adhere by muscles. Others construct it 
by agglutinating grains of sand, fragments of shells, and par- 
ticles of mud, by means of a membrane, which is doubtless 
also transuded. There are some, in fine, whose tube is almost 
entirely membranous, or horny. To the first of these belong, 
Serpula, Lin ., 
Whose calcareous tubes cover, by twisting round them, stones, 
shells, and all submarines bodies. The section ol these tubes 
is sometimes round, and sometimes angular, according to the 
species. 
The body of the animal is composed of a great number of 
segments. Its anterior part is spread into a disc, armed on 
each side with several parcels of coarse hairs, and on each 
* M. Savigny, joining the Arenicolce to this order, changes the name 
into Serpulacece. M. de Lamarck, adopting the same arrangement, 
changes the name Serpulacea into Sedentaria. My genera of Tubicolce are 
M. Savigny’s family of Amphitrite. With M. de Lamarck, they compose 
those of Amphitritea and Serpulacea. With them, M. de Blainville forms 
his order of Entomozoa cketopoda heterocrisina ; but contrary to his own 
definition he has introduced there Spio and Polydorus. 
