Dendronotus albus sensu Robilliard 1970

Dendronotus albus MacFarland, 1966

Fig. 7

Dendronotusalbus MacFarland, 1966: 275– 279, Pl. 40, Fig. 1; Pl. 46, Figs 1–4; Pl. 47, Figs 8 –11; Pl. 48, Figs 7, 8; Pl. 49, Fig, 5; Pl. 50, Fig. 4; Pl. 51, Figs 6, 7.

Dendronotus diversicolor Robilliard, 1970: 470–474, Figs 4–6, 25–28, Pl. 64, Figs 35, 36.

Not D.albus sensu Robilliard, 1970:466–470; Behrens, 1980: 72; Behrens and Hermosillo, 2005: 93; McDonald, 1983: 172; McDonald, 2009: 463 = D. robilliardi Korshunova, Sanamyan, Zimina, Fletcher, Martynov, 2016.

Extended diagnosis. Body relatively narrow. Four to five pairs of branched dorsolateral appendages, digestive gland penetrates only two pairs of dorsolateral appendages. Up to six appendages of oral veil. Three to seven appendages (external longest) of rhinophoral stalks. Lateral papilla of rhinophoral sheaths present. Rhinophoreswith 12–21 lamellae. Two to eight lip papillae. Basal colour translucent white to violet, dorsolateral appendage variable opaque orange or opaque white, including tip. Dorsalprocessesof jaws inclined posteriorly at approximately 50–60° to the longitudinal axis of the jaw body and 0.4–0.47 of its length. Masticatory borders apparently with ridge-like structures and denticles. Radula with up to 38 rows of teeth. Central tooth with up to 25 small distinct denticles without furrows. Up to nine lateral teeth with up to 14 denticles. Ampulla voluminous, folded. Bursa copulatrix large, oval. Seminal receptaculum very small and placed distally at a short distance from the vaginal opening. Prostate discoid with about 10–30 alveolar glands. The vas deferens is relatively short, bent, penis short, nearly straight, tapering to a blunt tip. Body length upto 73 mm.

Distribution. NE Pacific: California to southern Alaska, Canada and US. Records from Baja California, Mexico, need verification.

Bathymetry. Intertidal to at least 30 m depth.

Remarks. Dendronotusalbus has for almost 50 years persistently been confused with D. robilliardi. Despite this, D. albus is readily distinguished from D. robilliardi by the number of dorsolateral appendages (four to five in D. albus vs. five to eight in D. robilliardi) and the number of dorsolateral appendages into which the digestive gland branches penetrate (only in two anterior pairs in D. albus vs. three to six pairs including posterior ones in D. robilliardi). See Korshunova et al. (2016a) for discussion.