Type locality: off New England, 40°17N, 67°05W, 2320 m.
Remarks. This species can easily be separated from P. packardi by being more slender and by its pointed, not obtuse, protoconch. It resembles P. bureaui very much, but that species has a smaller protoconch and a number of spiral threads in the subsutural zone, which are absent in benedicti From demosia, also rather close, it can be separated by its bigger protoconch and longer siphonal canal. P. eurybrocha resembles benedicti considerably, but benedicti has a much coarser spiral sculpture of 2-3 primary ribs and numerous secondary smaller ribs on both sides and between them, while eurybrocha has a single secondary spiral or none at all between the primary ribs. Also the larval shell is considerably smaller in eurybrocha.