The first segment dorsally reduced. Ventral tentacular cirrus of second somite of a thin or foliaceous and asymmetrical form. Other tentacular cirri subcylindric, reduced distally to a pointed tip, that of I about half as long as the dorsals of II and III. Paired tentacles short, proximally thick and convexly bulging, abruptly narrowed to an acute tip with incurving sides. Unpaired tentacle situated between eyes in line connecting their centers, nearly of same length and size as the first tentacular cirri and about as long also as prostomium; annulate. Prostomium shortly subcordate, well rounded in front, incurved caudally. With very large cirri of which the dorsals widely overlap in the middle and thus completely cover the dorsum, the prostomium normally also being wholly concealed from above. The neurocirrus of a typical parapodium is attached by a broad base extending from a pronounced ventral swelling or flange (neurocirrophore) across the caudal side of the parapodium to its dorsal edge and projects farther dorsad of the parapodium than ventrad, the dorsomesal end widely rounded; much broader dorsoventrally than long, with the free edge evenly rounded. The notocirrophore in a thick rounded body arising from the base of the parapodium proper and showing the notopodium as a proportionately much smaller lobe on its ectal side; the style is attached about its caudal half-circumference and is broadly subreniform with the free margin coarsely crenulate or wavy, its mesal limb widely overlapping that of the opposite notocirrus and its ectal one overlapping the neurocirrus. Surface of cirri and of somites, especially ventrally, densely covered with very fine brown dots or points. Number of segments in type, near seventy-three. Body narrowing caudad, becoming narrow and pointed at posterior end. Proboscis unknown. Length, 19 mm. Type--M. C. Z. 2, 143. Dredged. Brown in life, this color being also retained in the preserved type specimen. A paratype has a greenish cast. This species suggests _Notophyllum imbricatum_ Moore in the large imbricated notocirri covering the dorsum but in the latter all the tentacular cirri are of the elongate, symmetrical, evenly tapering form characteristic of its genus. _Imbricatum_ similarly presents nuchal appendages, but these are three in number on each side and slender, instead of two broad, subelliptic lobes. The neuropodium is distally narrowed instead of broad, the head is differently formed, and various other differences are present throughout. _Steggoa gracilior_ sp. nov.