While the type of this species includes only the anterior end of the body, its characters seem sufficiently marked for subsequent identification. As in _lampra_, the anterior segments are darkened with purplish brown pigment, especially adjacent to the setigerous papillæ and about the tori, the ventral plates, however, remaining pale. Branchial membrane also pigmented caudally, and the branchiæ transversely banded. Only two eyes on each side are present in the type, a single one each on the second and third radiole from the dorsal end of the series. These eyes are exceptionally large and prominent, much larger than in any of the other species here recorded, embracing practically the entire width of the stalk. The free dorsal edges of the branchial membrane nearly straight, each with only a very slight angulation near its anterior end, not being truly lobate. Nine pairs of radioles. Minor dorsal lobes of collar prominent, produced well forward, curving a little mesad distally, the mesal edge reflected down the dorsal groove as usual. Width, .75 mm. Length of branchiæ, 2.5 mm. Type--M. C. Z. 2, 177. _Pseudopotamilla scotia_ sp. nov. Differing from the other species here described in having nine setigerous thoracic somites. Anterior somites of thorax darkened above, down the sides on both sides of the tori and also more or less ventrally with purplish brown pigment. Processes or lobes on free edge of branchial membrane above almost of same form as in _P. lampra_ and similarly overlapping. Nineteen pairs of branchial radioles. No eyes. Ventral lobes of collar prolonged, subacute, not overlapping. In the dorsal fasciæ of the ordinary thoracic somites the dorsal setæ are arranged mostly in more or less single, curved, longitudinal series, the clavate ventrals being arranged in two vertical series at right angles to the line of the dorsals. Pennoned setæ of the uncinigerous tori very prominent. Only a few of the most anterior abdominal segments present in type. Greatest width, 2 mm. Length of branchiæ, 4 mm. Type--M. C. Z. 2, 178. Taken in a large white sponge. SERPULIDÆ _Eupomatus intereans_ sp. nov.