28 POPULAR CONCHOLOGY. 



PART I. 



ANNUL AT A.* 



Lamarck has divided his class Annelides into 

 three parts : as the animals of two of these do 

 not form any covering to their bodies, they 

 will not be described here ; but the third divi- 

 sion, namely, the Sedentaria, will be admitted, 

 inasmuch as specimens of the tubes they form 

 are often met with in collections of shells. 



The animals of the tribe Annulata sedenta- 

 ria are soft, elongated, and worm-shaped, in- 

 habiting a tube which they never entirely quit. 

 The body has either transverse segments or 

 wrinkles; the head, eyes, and antennas are 

 sometimes deficient, and they have no feet, 

 but are furnished with retractile knobs, in 

 lateral rows. They are usually found attached 

 to marine substances, and inhabit tubes, either 

 membranous or horny, more or less encrusted 



* From annulus, Lat., a ring. 



