SERPULA, 
111 
The concamerated varieties which are found 
among the serpulse do not deserve a separate di- 
vision, because the conformation appears to ori- 
ginate not in any specific difference, but in an in- 
stinctive desire of the animal, for some important 
purpose, to increase the length of the shell without 
materially adding to the size of his apartment. 
The chambers are not connected with each other 
by any siphunculus or opening ; the last can there- 
fore only be inhabited. No sign of the internal 
dissepiments is visible externally, except in one 
species, S. Polythalamia, 
In this genus, as well as in the preceding one, 
the animal has been supposed to live with little or 
no adhesion to his shell ; but the degree and mode 
of his attachment are doubtless as various as the 
peculiar specific forms. 
The creeping, tortuous character of the first 
division of Serpula furnishes us with a clue to the 
etymon of the generic name, to Serpo. 
