d.i: 



Fig. 179. General dissection of Arenicola marina. After Ashworth. aff.h.v., 

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

 d.v.y l.v. dorsal and lateral blood vessels; nephr. nephrostome; not.ni. 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. 



BI 16 



