470 ANNELIDES. 



GoRDius, Lin. 



The body resembling a thread, the only mark of the articulations 

 being slight, transverse plicae; it has neither feet, branchiae, nor ten- 

 tacula. Internally, however, a nervous system is perceptible in a 

 knotted cord. Perhaps it will be necessary in the end to place them 

 atnong the cavitary Intestina, like the Nemertes. 



They live in fresh water, in the mud, and in inundated grounds 

 which. they perforate in every direction. 



The different species are not yet well distinguished; the most 

 common — Gordius aquaticus, L., is several inches in length, 

 almost as fine as a hair, and brown, with blackish extremities. 



