ANNUL AT A. 



29 



with grains of sand or fragments of shells, or 

 solid and calcareous : there are 4 families, and 

 the greater part of them are carnivorous. 



Family 1. — Dorsaliadce.* 



The branchiae of the animals of this family- 

 are disposed lengthwise on the body ; there are 

 2 genera : — 



1. Aeenicola. This genus is found on the 

 sandy shores of Europe, and is much used as a 

 bait for fish. " The animal bores for itself a 

 passage through the sand, and secures the 

 sides of the passage from falling in by applying 

 to them a glutinous cement, which unites the 

 particles of sand into a kind of wall or coating. 

 This covering does not adhere to the body, 

 but forms a detached tube, within which the 

 animal moves with perfect freedom, and which 

 it leaves behind it as it progressively advances ; 

 so that the passage is kept pervious through- 

 out its whole length, by means of the lining, 

 which may be compared to the brickwork of 



* Les Dorsalees, Lamarck. 



