Macrostylis obscurus (Brandt, 1992) Brandt, 1992

Riehl, Torben & Brandt, Angelika, 2010, Descriptions of two new species in the genus Macrostylis Sars, 1864 (Isopoda, Asellota, Macrostylidae) from the Weddell Sea (Southern Ocean), with a synonymisation of the genus Desmostylis Brandt, 1992 with Macrostylis, ZooKeys 57, pp. 9-49 : 36-37

Macrostylis obscurus (Brandt, 1992) comb. n. Fig. 19

Desmostylis obscurus Brandt, 1992, p. 69-74, Fig. 11-13

Additions to original description.

Pereopod 4 relative article length ratios: 1:0.5:0.5:0.4:0.3:0.1, basis 2.3 times longer than wide, with at least 5 broom setae, 1 short simple seta distodorsally; ischium 1.8 times longer than wide, with 1 short simple seta distodorsally; merus almost 1.8 times longer than wide, distodorsally with 1 stout bifurcate seta, distoventrally 2 acute simple setae, 1 reaching beyond propodal articulation; carpus 1.6 times longer than wide, distodorsally with 1 bifurcate seta, 1 broom seta distoventrally next to 1 long simple seta exceeding dactylus in length; propodus twice as long as wide, dorsally expanding into a distal lobe, with 1 long bifurcate seta distoventrally, exceeding dactylar claw, and 1 short and simple seta ventrally; dactylus small, twice as long as wide, about half propodus length and width, with 1 terminal stout and acute claw, 1.5 times article length, and 1 subterminal bifurcate claw, shorter than article, 2 setae terminally and 1 thin and long simple seta subterminally, twice as long as article.

Pereopod 5 propodus 3.3 times longer than wide, with 2 long simple setae distoventrally, thinner seta more than twice as long as dactylus, the stouter one almost reaching the tip of dactylus, 1 simple seta ventrally; dactylus 5 times longer than wide, half propodus length, with 3 simple, acute claws, terminal claw longer than dactylus, subterminal claw stout, robust and shorter than dactylus, second subterminal claw slender and more than twice as long as dactylus.

Pereopod 6 propodus expanding into a distal lobe, with 1 long bifurcate seta, reaching beyond tip of dactylus, with 1 very long and simple seta and 1 broom seta; dactylus 4.3 times longer than wide, with 1 terminal long and acute claw, 1.5 times dactylus length, and 1 subterminal claw, longer than article, with 2 thin and unequally long simple setae subterminally.