Planche 1 issued from : E.L. Markhaseva & F.D. Ferrari in Invert. Zool., 2005, 2 (2). [p.142, Fig.18].
Female (from holotype): A, posterior prosome and urosome (lateral, right side); B, A2 (exopod); C-D, Md (gnathobase; posterior and proximal, respectively); E, Mx2 (praecoxal, coxal and proximal basal endites); F, Mx2 (sensory setae of distal basal endite + ramus); ; G, Mxp (syncoxa); H, P1 (distal part of basis and endopod; anterior).
Scale bars: 0.1 mm.

Nota: Prosome 4.6-5.4 times longer than urosome.
- Cephalosome fused with pediger 1, pedigers 4 and 5 fused dorsally, separate laterally.
- Anterior cephalosome rounded dorsally.
- Posterior corners of prosome produced into short, indented lobe in lateral view.
- Genital complex symmetrical, spermathecae elongate, dorsal part directed dorsally.
- Rostrum: 2 short, thin filaments.
- A1 24-segmented.
A2 coxa with 1 seta; basis with 2 setae; endopod 2-segmented, proximal segment with 1 seta; distal with 14 (6 terminal and 8 sub-terminal setae); exopod 8-segmented with 1, 3, 1, 1, 1, 1, 1, 3 setae.
- Md gnathobase with tooth-like knob on posterior face, cutting edge wide with 8 teeth and 1 seta; basis with 3 setae; endopod 2-segmented, proximal with 2 setae, distal with 9 setae; exopod with 1, 1, 1, 1, 2 setae.
- Mx1 praecoxal endite with 2 posterior and 9 terminal setae, proximal 2 terminal setae curved proximally; coxal endite with 2 setae, coxal epipodite with 7 setae; proximal basal endite with 2 setae, distal with 3 setae (1 of them small); endopod with 7 setae in groups of 2+5; exopod with 4 setae.
- Mx2 proximal praecoxal endite with 4 setae, distal with 3 setae, 1 thicker; proximal coxal endite with 3 setae, 1 thicker; distal with 3 setae, 1 thicker; proximal basal endite with 4 setae, 1 thicker, 1 worm-like; distal basal endite +ramus with 5 worm-like and 3 brush-like sensory setae, 1 brush-like seta thicker and with longer setules.
- Mxp praecoxal endites of syncoxa with 1, 2, 3 setae, 1 worm-like; coxal endite with 3 setae; basis with a row of small denticles proximally, 3 medial setae, 2 setae on distal endite; endopod of 5 segments with 4, 4, 3, 3+1 lateral and 4 setae.
- P1 coxa without seta; basis with medial seta; endopod with 3 medial and 2 terminal setae; Von Vaupel Klein's organ with basal seta slightly curved, anterior knob rounded and with denticles; exopod 3-segmented, proximal with 1 lateral seta, middle with 1 medial and 1 lateral seta, distal with 3 medial, 1 terminal, 1 lateral seta; lateral seta on proximal segment exceeds the base of lateral setae of following segment, lateral seta on middle segment exceeds half length of lateral seta of terminal segment.
- P2-P4 as described by Grice & Hulsemann (1970).
- P5 3-segmented: exopod (distal segment) with 1 long medial and 1 short lateral setae, and 1 subterminal and 1 terminal attenuation.
- Caudal rami with 4 large, thick terminal setae, 1 small dorsal seta and 1 small medial ventral seta.

Planche 2 issued from : E.L. Markhaseva & F.D. Ferrari in Invert. Zool., 2005, 2 (2). [p.137, Table 2].
Byrathis macrocephalon (Selected character states of species included in Byrathis gen. n.).
Ce = cephalosome; Mn = mandible; Pd = pediger segment; Ri = endopod; Re = exopod

Planche 3 issued from : E.L. Markhaseva & F.D. Ferrari in Invert. Zool., 2005, 2 (2). [p.138, Table 2 (contituing)].
Byrathis macrocephalon (Selected character states of species included in Byrathis gen. n.).
Ri = endopod; Re = exopod.

Planche 4 Issued from : G.D. Grice & K. Hülsemann in Bull. Mus. Comp. Zool., Harvard, 1970, 139 (4). [p.208-209, Pl. VI, Figs. 111-116]. As Xanthocalanus macrocephalon.
Female (from 39°45.2'N, 70°33.8'W): 111-112, habitus (lateral and dorsal, respectively); 113, forhead (lateral); 114, same (ventral); 115, 5th thoracic segment and urosome (lateral); 116, right A1.

Nota : - Head and 1st thoracic segment fused, separation indicatd laterally by short line, 4th and th seggment incompletely separated.
- Abdomen 4-segmented.
- Rostrum small without filaments.
- Posterolateral margin of 5th thoracic segment angular.
A1 reaching end of cephalothorax, segments 8 and 9 fused.
- Exopod of A2 twice the length of endopod.
- Basal segment of Md palp with 3 setae ; conspicuous hump on external side of Gnathobase ; teeth on chewing edge small.
- Mx1 with 1st inner lobe bearing 10 spines, 2nd and 3rd inner lobes and 2nd basal segment each with 2 setae , 2 and 5 setae on endopod, 4 setae on exopod.
- Mx2 1st lobe with 4 setae, 2nd to 4th lobes each with 3 setae, 5th lobe with 3 setae, 1 small spine and 1 sensory appendage ; endopod with 2 types of sensory appendages.
- Endopod of P1 1-segmented, of P2 2-segmented, of P3 to P4 3-segmented ; exopods of all four legs 3-segmented. In P2 to P4 posterior sides of endopods armed with spinules, in P4 also basipod and exopod.
- P5 3-segmented, on posterior side, mainly externally, covered with small spines. Terminal segment with 1 small external spine, 1 long internal spine and 2 terminal points, not articulating with the segment.

Planche 5 Issued from : G.D. Grice & K. Hülsemann in Bull. Mus. Comp. Zool., Harvard, 1970, 139 (4). [p.210-211, Pl. VII, Figs. 117-127]. As Xanthocalanus macrocephalon.
Female: 117, A2; 118, Md palp; 119, Md (masticatory edge); 120, Mx1; 121, Mx2; 122, Mxp; 123, P1; 124, P2; 125, P3; 126, P4; 127, P5.