Coryphella gracilis (Alder & Hancock, 1844)
Only surface pigment on the body is the discontinuous, white, medial line, often reduced to a few dots or absent, on the tail.
Subapical white ring on cerata is fragmentary and narrower than on C. browni. Maximum length 15 mm.
Length 7 mm, adult with round, white blobs of ovotestes visible. Outer Hebrides, Scotland. April 2018. Leg. S. Taylor.