ARENICOLA 



103 



5. Locate the anterior, terminal mouth and posterior, 

 terminal anus. 



6. Nephridiopores, situated just ventral to the neuropodia 

 of the fifth to tenth setigerous segments are not easily visible 

 under ordinary conditions. 



7. Study the segmentation of the worm and note that the 

 annuli and segments are not homologous. Where parapodia 



* Septa begin again in extreme posterior part of worm. There are dorsal and ventral mesenteries 

 in the 3rd and 4th segments. 



