Phylum Mollusca and Minor Eucoelomate Phyla 485 



The tentacles are arranged on a horseshoe-shaped lophophore v/ith 

 the mouth opening within the lophophore, and the anus just outside. 

 The coelom is divided into compartments and there are two nephridia 

 which open near the anus. There is a nerve ring at the anterior end. A 

 series of complicated blood vessels carry the blood with the hemoglobin- 

 containing corpuscles to all parts of the body. 



Feeding is made possible, as in the Bryozoa and Brachiopoda, by 

 the cilia on the tentacles. Currents of water with minute particles of 

 food are drawn in. The food is trapped by mucus. 



The phoronids are monoecious animals. The eggs and sperm pass 

 through the nephridia to the outside. A trochophore-like larva develops 

 which, after a period of swimming, metamorphoses into the typical adult. 



