The prostomium extends as a convex hood or inverted scoop above the mouth; along its posterior border is a series of long, crowded, tentacles. The prostomial fold behind the tentacles is crossed by a transverse band of distinct eyes, the band narrow above and widening on each side. Mouth a crescentic slit with corners curved caudad; bordered behind by a thick lip the anterior median edge of which is truncate. No dorsal cirriform process on III or any other segment, all being wholly smooth. A characteristic of the species is the large number of setigerous segments, at least thirty-one being present (IV-XXXIII) in the type, and possibly more. The setæ differs from those of nuda in their longer fine tips and more geniculate appearance at base of this region. The uncini are characterized by an exceptionally long beak which, beyond its strongly curved base is straight; the sinus narrow, the process arising near its middle, low obtuse; vertex not comparatively high, crossed by mostly four series of denticles; body of uncinus rather narrow, the shoulder on convex side much farther toward the end than, e.g., in nuda and well below level of bottom of sinus. The type is incomplete, only near thirty-eight segments being present. The color is noted as pinkish in life. At present it is fulvous in the type.

Length of incomplete specimen not in excess of 12 mm.; greatest width, .8 mm.

Type—M. C. Z. 2, 167.

Pista fratrella sp. nov.

This form seems to be close to P. alata Moore. The type, which is much smaller than that of alata, differs in various details from the description of the latter. The principal lateral wings are confined to the third segment and are united across the dorsum of third somite instead of involving the anterior border of IV and crossing the latter above; connecting dorsal fold low and lacking any forwardly directed process; the wing rises as a high, rounded lobe on each side just below level of setigerous tubercles, rising high above the middorsal surface. In addition to the prominent wings on III there is on IV on each side a much lower ridge or wing paralleling that on III, this not more prominent above. Unlike those of alata, somites II and III are not confounded laterally but are distinct throughout. Prostomium short. Tentacles mostly lost in type; rather slender, not long, apparently in but a single transverse series. Peristomium deeply excavated at middle below, the bottom of the excavation rounded and the peristomium produced on each side of this into the usual large lobes. The branchiæ, as in the genotype and other species, strongly asymmetrically developed. The right anterior branchia is much the largest, the trunk very long, with the left anterior much smaller. Of the posterior pair, the right, unlike that of alata, is also much larger than the left one. In the type the sternal plates are not sharply differentiated. The manubriate uncini of V have the general form of those in alata, but the bulge below the beak is much larger and more rounded with the subrostral tooth more obtuse and nearer the middle of the oblique edge; beak less divergent from manubrium; vertex with three transverse series of denticles. The color in the abdominal region light fulvous, in the thoracic darker with a narrow brownish stripe along caudal border of each segment laterally and ventrally. Type not quite complete caudally, retaining eighty somites.

Length, 36 mm.; greatest width, 2.8 mm.

Type—M. C. Z. 2, 168.

The wall of the tube is composed of sand and shell fragments.

Naneva gen. nov.

Prostomium short; with numerous tentacular filaments. Uncini avicular and of same form throughout. Setæ beginning on third somite; tips simple. Uncini beginning on the fourth somite. No lateral foliaceous lobes on the anterior segments. Branchiæ two pairs; branched; attached on somites II and III.