108 ANNELIDA. 



while floating in the coelomic fluid. They pass out through 

 the nephridia, which function as gonoduds. 



Nervous System. Does the ventral nerve-core seem to be 

 double? Is it ganglionated? Does it give off lateral nerve 

 branches? Trace the circum-esophageal connectives to the supra- 

 esophageal ganglion. The ganglion is small and situated behind 

 the crown of tentacles, to which sensory nerves extend. Does 

 any system of organs show segmentation? 



Make a drawing to show the internal anatomy. 



Gerould: The Development of Phascolosoma. Zool. Jahrb., 23, 1906. 

 C. B. Wilson: Our North American Echiurids. Biol. Bui., 1, 1900. 



