Priotrochus obscurus is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails. Subspecies \n* Priotrochus obscurus obscurus (Wood, 1828) (synonyms: Gibbula (Priotrochus) sepulchralis (Melvill, 1899); Gibbula sepulchralis (Melvill, 1899); Priotrochus sepulchralis Melvill, 1899; Trochus nabateus Issel, 1869; Trochus signatus Jonas, 1844) \n* † Priotrochus obscurus ponsonbyi (G. B. Sowerby, 1888) (synonyms: Monilea (Priotrochus) ponsonbyi (G. B. Sowerby, 1888); Monilea obscura ponsonbyi (G.B. Sowerby, 1888); Monilea ponsonbyi (G.B. Sowerby, 1888); Priotrochus alexandri Tomlin, 1926; Trochus (Gibbula) ponsonbyi G. B. Sowerby, 1888; Trochus ponsonbyi G.B. Sowerby, 1888)