<i>Macrostylis roaldi</i> sp. nov., paratype adult male (ZMH-K42993), posterior pereopods.

<p>A) pereopod VI. lateral, B) pereopod VII, lateral, C) pereopod V, lateral. Scale = 0.3 mm.</p

<i>Macrostylis roaldi</i> sp. nov., paratypes (ZMH-K42999), adult male, SEM.

<p>A) habitus, lateral, B) habitus, dorsolateral, C) antennula, antenna, basal segments, D) cephalothorax, dorsolateral, E) cephalothorax, antenna, lateral, F) cephalothorax, mouthparts, ventral. Scales: A, B = 0.5 mm, C–F = 0.1 mm.</p

Material of previously described Antarctic and South Atlantic Macrostylidae studied for comparison with <i>Macrostylis roaldi</i> sp. nov.

<p>BM(NH)  =  British Museum of Natural History, London, UK; ZMH  =  Zoological Museum, University of Hamburg, Germany.</p

12S, 16S and COI primers.

<p>12S, 16S and COI primers.</p

<i>Macrostylis roaldi</i> sp. nov., paratype adult male (ZMH-K42993), anterior pereopods.

<p>A) pereopod I, lateral, B) pereopod II, lateral, carpo-propodal articulation twisted, C) pereopod III, lateral, D) pereopod IV, posterior. Scale = 0.3 mm.</p

<i>Macrostylis roaldi</i> sp. nov., paratype female (ZMH-K42995).

<p>A) habitus, lateral, B) habitus, dorsal, C) antennula and antenna, lateral, in situ D) operculum, ventral, E) uropod protopod (endopod broken, missing), enlarged, F) setae from setal ridge, latero-ventrally on pleotelson in top-to-bottom order: simple, split, split and pappose, pappose, G) pleotelson, ventral. Scale bars = 0.5 mm.</p

<i>Macrostylis roaldi</i> sp. nov., paratype female (ZMH-K42995), pereopods.

<p>A) Pereopod I, lateral, with enlarged setae (medially biserrate, distally fringe-like sensilla and distally fringe-like sensilla), B) pereopod II, lateral, C) pereopod III, lateral, D) pereopod IV, posterior, E) pereopod VI, medial, F) pereopod VII, medial. Pereopod V not shown, broken, missing. Scale = 0.5 mm.</p

<i>Macrostylis roaldi</i> sp. nov., mouthparts: paratype adult male (ZMH-K42993, A-C, E-F, H-I), paratype female (ZMH-K42995, D, G).

<p>A) left mandible incisive process and lacinia mobilis, medial, B) paragnaths, C) left mandible, D) right mandible incisive process and lacinia mobilis, medial, E) maxillula, dorsal, F) right mandible, G) maxilla, dorsal, H) maxilliped, ventral, I) maxilliped endite and palp, dorsal, setae omitted. Scales = 0.1 mm.</p

<i>Macrostylis roaldi</i> sp. nov., paratype juvenile male (ZMH-K42997).

<p>A) habitus, lateral, B) habitus, dorsal, posterior pereonites damaged, C) pleotelson, ventral, D) left pereopod III, E) right pereopod III. Scales: A, B = 0.5 mm; C = 0.2 mm; D, E = 0.3 mm.</p

<i>Macrostylis roaldi</i> sp. nov., paratype ovigerous female (ZMH-K42998).

<p>A) habitus, lateral, B) habitus, dorsal, C) antennula and antenna, lateral, in situ D) pleotelson, ventral, E) pereopod III, F) uropod, enlarged, endopod broken, missing, G) pereopod V, basis, baso-ischial articulation and dactylus damaged. Scales A–B, D = 0.5 mm, C, E, G = 0.3 mm.</p