ROTIFERS. 209 



protection, if any. The Eotifers are somewhat trumpet- 

 shaped when extended, and to a certain extent resem- 

 ble Megalotrocha (Fig. 147). The ciliary disk is single 

 and horseshoe shaped. It is closed and drawn partly 

 into the body when the Rotifers retire into their apol~ 

 ogy for a sheath, as they often do, the whole colony 

 continually waving and bobbing and bowing as the 

 members retire, or ascend and expand themselves. The 

 sheaths usually form a little mass of jelly-like sub- 

 stance, from all parts of which the Rotifers project. 

 The colonies are commonly adherent to Ceratophyllum 

 or Myriophyllmn. 



2. STEPHANOCEROS (Fig. 142). 



The body of this the most beautiful of all the Roti- 

 fers is somewhat spindle-shaped. It ends in a long, flex- 

 ible, tail-like foot which is attached to some submerged 

 object, and has five long, slightly curved arms 

 arranged in a row about the edge of the front 

 border. These arms are held aloft and form 

 a most effectual trap for wandering Infusoria, 

 which are attracted or drawn into it by some 

 means not easy to make out. The front of 

 the body is like a deep open funnel leading 

 down to the mouth, mastax, and stomach. 

 The ordinary ciliary disk is absent, being re- 

 placed by the arms, but around the inside border of 

 the funnel -like front there seem to be many fine 

 cilia which may produce the currents in the water. 



