(from 1912 Wijnhoff, G. List of nemerteans collected in the neighbourhood of Plymouth from May - September, 1910) Bodywall composed of an epithelium in which a separate layer of gland-cells does not exist, the basal membrane, the outer circular and the inner longitudinal muscle layer. The inner circular muscle layer often fails. The nervous system is situated in the middle of the inner longitudinal muscle layer. Sense organs are not developed. Four thick cephalic nerves. Vascular system consisting of a pair of lateral blood-vessels only. A great number of nephridial organs.
