MaleMusFIG 3: The M lineage.

(L) Left; (R) right; (ail and pil) anterior and posterior inner longitudinal; (aob and pob) anterior and posterior oblique; (aol and pol) anterior and posterior longitudinal; (cc) coelomocyte; (cdl) caudal outer longitudinal; (dgl) diagonal; (gec) gubernacular erector; (grt) gubernacular retractor; (vsr and dsr) ventral and dorsal spicule retractors; (vsp and dsp) ventral and spicule protractors.