WHEEL-BEABEES. 291 



volutions or constrictions, but apparently granular in its 

 texture. The alimentary canal is bent upwards through 

 the whole length, terminating in an orifice behind the 

 rotatory organ ; for though I have not traced it when 

 empty, I have seen the fsecal matter driven rapidly up- 

 ward as through a canal, until the mass was discharged 

 just behind the sinuous cleft. On our mixing carmine 

 with the water the eifect is very striking ; the particles, 

 whirled round in two circular vortices, are poured in 

 an accumulated torrent through the sinuosity, and over 

 the elevation at the front of the head. We presently 

 perceive a slender line of crimson passing down below 

 the mastax, which iadicates a slender stomach-tube 

 there ; and, after a while, a little ball of the same pig- 

 ment accumulates and is seen resting a little lower 

 down. This then indicates the form and position of 

 the stomach ; it must be a very slender canal, termi- 

 nating in a small rounded bag, at about one-third of the 

 distance from the mastax to the base of the tube. 



■WHEELS OF TUBE-WHEEL. 



The lengthened sac which you see is the ovary, from 

 which the eggs are discharged into the lower part of 

 the case. 



The mouth needs a little explanation in detail. As 



