(from Coe, W. R. (1905). Nemerteans of the west and northwest coasts of America. Bull. Mus. comp. Zool. Harv.. 1-318)

Body very long and slender, varying greatly in thickness according to state of contraction, but most commonly considerably flattened; often sharply bent and folded into an irregular mass; integument provided with an unusual abundance of mucous secretion; proboscis and mouth opening together on subterminal portion of snout; proboscis sheath limited to anterior third of body; proboscis slender and very short, often not more than 1/6 the length of the body; a large number of minute eyes usually present; cerebral sense organs situated well in front of brain, and usually very small. The species are of sluggish movement, and many of them are found very near high water mark among mussels, barnacles, rockweeds, etc.