IEPAS. 29 



groups, adhering by their flexible stems, to shipping, or 

 floating pieces of wood. They seem to delight in situa- 

 tions exposed to the strong motion of the waves, and there- 

 fore often place themselves near the rudder of the ship, 

 where the agitation of the water is most considerable. 

 The singular animal which these shells contain, and 

 which differs in nothing essential from that of the conical 

 shells, is furnished with a plumose fringe, divided into 

 twenty-six filaments, or tentacula, of different lengths : 

 the shortest are situated on each side of the mouth, and 

 do not appear on the outside of the shell. Each fila- 

 ment is articulated throughout its length, and from each 

 joint proceeds a bunch of very delicate hairs. These 

 tentacula, or feelers, are supported, two by two, on fleshy 

 pedicles. The flexible trunk with which this animal is 

 provided, is rather longer than the tentacula ; and the 

 mouth, which is placed immediately below it, is of an 

 oval shape, and closed by a scaly operculum. The 

 digestive organs are represented in the Lectures on Com- 

 parative Anatomy, by Sir Everard Home, vol. 2. pi. 75. 



We are not acquainted with the nature of the nourish- 

 ment by which these animals are sustained ; but it pro- 

 bably consists of such minute worms, and sea insects, 

 as come within the reach of their feelers, for those parts 

 are kept very actively employed while the animal is in 

 search of food. 



We have no particular observations on the mode by 

 which these flat shells increase in size ; but if we may 

 judge from inspection, it appears that their ligaments 

 separate, and that the enlargement takes place from the 

 curved edge of the valves. New shelly matter may 

 there be deposited from time to time, till the animal has 

 attained its full growth ; and in this case the extremities 



