FIGURE 22 in Southern Ocean Macrostylidae reviewed with a key to the species and new descriptions from Maud Rise

FIGURE 22. Illustrations for identification key to the Macrostylidae of the Southern Ocean. A, pleotelson of Macrostylis cerrita Vey & Brix, 2009, dorsal view, evenly narrowing towards uropodal insertions, lateral margins straight, waist absent. B, pleotelson of M. matildae n. sp., dorsal view, evenly narrowing towards uropodal insertions, lateral margins straight, waist present. C, pleotelson of M. gerdesi (Brandt, 2002), dorsal view, lateral margins straight, subparallel. D, pleotelson of Macrostylis setulosa Mezhov, 1992, lateral margins convex, waist present. E, pleotelson of M. antennamagna Riehl & Brandt, 2010, dorsal view, lateral margins convex, waist present, posterior apex concave. F, ventral spines of M. matildae with pereonites 3 and 4 spines present, pereonite 7 spine small. G, ventral spines of M. roaldi Riehl & Kaiser (2012) with pereonites 3 and 4 spines present, pereonite 7 spine prominent. H, ventral spines of M. scotti n. sp. with pereonites 3 and 4 spines absent, pereonite 7 spine small. I, M. matildae pereonite 3 posterolateral margin spine-like setae absent, pereonite 4 lateral margin curved, posterolateral margin produced posteriorly, rounded, spine-like setae present. J, M. scotti pereonite 3 posterolateral margin spine-like setae absent, pereonite 4 lateral margin convex, posterolateral margin not produced posteriorly, rounded, spine-like setae absent. K, M. roaldi pereonite 3 posterolateral margin spine-like setae present, pereonite 4 lateral margin curved, posterolateral margin produced posteriorly, pointed, spine-like setae present. L, M. matildae operculum, elongate, distally tapering, with lateral fringe of setae distinctly separate from apical row of pappose setae. M, M. scotti operculum, elongate, ovoid, with fluent transition between lateral fringe of setae and apical row of pappose setae. N, M. roaldi operculum, stout, ovoid, with lateral fringe of setae distinctly separate from apical row of pappose setae. O, M. cerrita pereopod III ischium with tapering dorsal apex and 1 spine-like prominent seta. P, M. roaldi pereopod III ischium with triangular dorsal apex and 1 prominent spine-like seta. Q, M. scotti pereopod III ischium with dorsal apex tapering and 2 prominent, spine-like setae.