132 DROPS OF WATER. 



in form to the last, though differing in many es- 

 sential particulars, is the Trachelius anas : it has 

 what at first sight might be taken for a neck, 

 but the mouth not being placed at the end, it 

 cannot be so considered. The mouth is at the 

 base of this long appendage, and may be seen 

 occasionally whilst the long process is waving 

 about ; this, and the cilia on the body, are the 

 organs by which it moves. 



Bursaria truncatella (Drop III. fig. 7) is 

 another marvellous being, large, and easily dis- 

 cernible by the naked eye ; found in water 

 where there are decayed beech-leaves. It is 

 oval in form, truncated in front, and having a 

 simple row of cilia there, but the body is entirely 

 covered with small ones disposed in rows. It 



