-s.o. 

 —nephr. 



yiot.m. 



.not.m. 



Fig. 190. General dissection of Arenicola marina. After Ashworth. aff.b.v., 

 eff.b.v. afferent and efferent vessels of gills and body wall; an. auricle, 

 d.v., l.v. dorsal and lateral blood vessels; nephr. nephrostome; not.m. noto- 

 podial muscles; oe.p. oesophageal pouch; sep. septa; s.o. segmental organ; 

 s.i.v. subintestinal blood vessel ; ven. ventricle ; v.n.c. ventral nerve cord ; v.v. 

 ventral blood vessel. The direction of the flow of blood is indicated by arrows. 



