cloaked by a dense growth of long filiform papillæ; with large clavate tips, these papillæ approximating the setæ in length. The papillæ also cluster densely about the notopodia, these papillæ having similar clavate tips. The papillæ of the general surface of dorsum, venter and sides are much shorter. Color nearly uniform greyish brown. Number of segments in type, forty-nine. Length, 13 mm. Type--M. C. Z. 2, 163. Taken in holdfasts of kelp, August 12, 1917. CAPITELLIDÆ _Natomastus angulatus_ sp. nov. In comparison with <i>N. tenuis</i> Moore, known from San Diego, this species differs in the form of the thorax, which is strongly angulate instead of terete the sides and venter being flat and the dorsum usually but little convex, so that the cross-section is nearly quadrate; also in having the segments and their subdivisions sharply separated with the posterior subsegment in each case much shorter than the anterior instead of equal to it. In the type the posterior thoracic somites are twice or more as long as wide, but in some paratypes the relative length is much less. Thorax narrowed caudad. The abdomen in its anterior part obviously thicker than the thorax in its widest part. The prostomium characteristic, showing two distinct regions, a broad posterior one with convex, anteriorly converging sides and a narrower, subconical, palpoidal terminal part sharply set off from the basal. Segments of abdomen irregularly multiannulate, sulci deep and surface usually appearing strongly rugose and uneven. Length near 160 mm.; greatest width of abdomen, 1.4 mm. Type--M. C. Z. 2, 164. Taken in sand and in growths of eel grass. The color is noted as reddish in life, as usual in the family. SPIONOIDEA _Morants_ gen. nov. Body with an anterior region of fifteen setigerous somites separated from a larger posterior region by a specialized somite, the sixteenth. Prostomium with a lateral process or horn on each side in front, notched in front at middle. Eyes none in genotype. Dorsal cirri present in addition to branchiæ on the first four setigerous somites. Notopodia with simple capillary setæ throughout. Anterior neuropodia with capillary setæ, but others also with crochets. Anal. cirri two. _Genotype_--_M. duplex_ sp. nov. _Morants duplex_ sp. nov.