A lineid heteronemertean, CRATICULINEUS novaezealandiae gen. et sp. nov., is described and illustrated. The most significant morphological features of the species are the extremely well developed longitudinal muscle plate, criss-crossed by connective tissue fibers, between the rhynchocoel and foregut, and the manner in which the excretory tubules lack external nephridiopores and discharge into the foregut lumen. The nemerteans were obtained from a 95 m depth .apprx. 140 miles east of Christchurch, New Zealand.