(Fig. 19A)
Eualus lineatus Wicksten & Butler, 1983: 3, figs. 1–2. — Wicksten 1990b: 593. — Jensen & Johnson 1999: 133. — Chace 1997: 43. — Jensen 2004: 468.
Spirontocaris herdmani Rathbun 1904: 100 [part, not Spirontocaris herdmani Walker, 1898].
Eualus herdmani Holthuis 1947: 11 (part). — Kozloff 1974: 166. — Butler 1980: 197, pl. 1C (part).
Diagnosis. Rostrum slender, not reaching end of second segment of antennular peduncle, with 3–6 dorsal, 1–3 ventral teeth. First segment of antennular peduncle with 3 spines, other two segments with 2 spines each, stylocerite reaching or surpassing end of first segment; with curved, dorsal spine near base. Carapace with small suborbital tooth, strong antennal tooth, moderate pterygostomian tooth. Pereopods 1–3 with epipods. Pereopod 1 stout. Pereopods 3–5 slender, with spinose dactyls. Merus of pereopod 3, with 3 spines; pereopod 4, with 2–3 spines; pereopod 5, with 0–1 spine. Pleura of abdominal somites 13 rounded, 4–5 with points. Telson with 3 pairs dorsolateral spines. Male total length 20 mm, female 25 mm.
Color in life. Carapace, abdomen marked with broad orange bands against translucent background (Jensen & Johnson 1999).
Habitat and depth. Rocks, rocky reefs; often among sponges, 12–232 m.
Range. Naha Bay, Alaska to Santa Cruz I., California. Type locality SW of Gull I., off Santa Cruz I., California.
Remarks. This species has been confused with Heptacarpus herdmani (Walker, 1898), despite Walker's original description, which stated that the species lacked an exopod on the third maxilliped. Heptacarpus herdmani is currently known only from the type specimen from Puget Sound. The species also was confused with E. subtilus Carvacho & Owen, 1984; but can be distinguished easily in life by its colorful stripes and larger size than E. subtilis (Jensen & Johnson 1999). Eualus lineatus seems to be more common in colder water north of Point Conception or in areas of upwelling along the islands of southern California.