(from Coe, W. R. (1905). Nemerteans of the west and northwest coasts of America.. Bull. Mus. comp. Zool. Harv.. 1-318)
General color of the body milk white and more or less translucent throughout. This color is somewhat affected, however, by the intestinal canal which is often pale yellowish or sometimes brownish. In the brain region there is often a rosy tinge. The esophagus shows all anterior translucent portion, while its posterior half is opaque white. Proboscis is small; white in color.
After preservation in formalin or in alcohol, there is commonly a marked differentiation of color in the anterior portion of the body, perfectly similar to the well-known dark band which occurs in most species of Tubulanus after preservation. About 5 mm of the anterior end of a medium-sized specimen is pure white, and this is followed by a sharply marked brownish or pale brick red band. This shades off gradually posteriorly, precisely as in Tubulanus, so that its exact width cannot be determined, but the brownish tinge is conspicuous for 2 mm or more in a specimen which measures 20 mm. long and 1 1/2 mm wide after preservation. In serial sections the position of this band can easily be distinguished with the naked eye because of the differential staining of the integument where it is present. This effect is apparently produced by a differentiation in the chemical nature of the glandular secretions, and not to any special pigment. Anteriorly, where the color is deepest, the layer of peculiarly stained glands occupies the inner two thirds of the integument, but the layer becomes gradually thinner posteriorly, until there are only a few scattered glands at the beginning of the intestinal region. The band is of the same thickness ventrally as dorsally, and begins anteriorly near the forward end of the nephridial region.
The lateral sense organs are easily distinguished with a hand lens on preserved specimens. They lie on the lateral margins of the body near the posterior border of the reddish brown band, and each appears as an oval depression bordered with a white or colorless rim. Naturally the sense organs show most conspicuously in those specimens which have the brownish band of the deepest color. The body usually shows an annular constriction just posterior to the sense organs, due to contraction of the powerful circular muscles.
A dorsal, longitudinal infolding of the integument can also he distinguished in the same region. This infolding will be described below.