Plate 1 issued from : E.L. Markhaseva & F.D. Ferrari in Invert. Zool., 2005, 2 (2). [p.133, Fig.12].
Female (from 13°23'N, 102°27'W): A-B, habitus (dorsal and lateral, respectively); C, rostrum (frontal view); D, posterior prosome, P5 and urosome (lateral); E, posterior prosome and genital complex ( lateral, left side); F, posterior prosome and urosome (dorsal); G, A1.
Scale bars: 0.1 mm.

Nota : Cepalosome and pediger segment 1 fused, 4th and 5th fused dorsally, separate laterally. Posterior corners of prosome produced laterally into a short, slightly indented lobe. Genital complex symmetrical in dorsal view with a slight bump laterally, a ventral bump in lateral view, and with small spinules dorsally and laterally on this and the following somite. Rostrum with 2 thin short filaments. A1 24-segmented. Caudal ramus with 4 terminal setae, 1 small dorsal seta and 2 subterminal setae ; with denticles.

Plate 2 issued from : E.L. Markhaseva & F.D. Ferrari in Invert. Zool., 2005, 2 (2). [p.134, Fig.13].
Female: A, A2; B, Mx2; C, Mx2 (sensory setae on distal endite + ramus); D, Mxp (syncoxa); E, Mxp (basis and endopod).
Scale bars: 0.1 mm.

Nota : A2 coxa with 1 small seta ; basis with 2 setae ; endopod 2-segmented, distal segment with 15 setae (7 terminal and 8 subterminal) ; exopodite 8-segmented with 1, 3, 1, 1, 1, 1, 1, 3 setae, respectively. 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.

Plate 3 issued from : E.L. Markhaseva & F.D. Ferrari in Invert. Zool., 2005, 2 (2). [p.135, Fig.14].
Female: A, Md (mandibular palp); B-E, Md (gnathobase,; anterior, distal, proximal and posterior, respectively); F, Mx1 (praecoxal endite; G, Mx1 (coxa, basis and rami).
Scale bars: 0.1 mm.

Nota : Md gnathobase with tooth-like knob on posterior face, cutting edge broad, with 8 teeth and 1 seta ; endopod 2-segmented, proximal segment with 1 seta, distal with 9 setae ; exopod with 1, 1, 1, 1 and 2 setae. Mx1 praecoxal endite with 2 posterior and 9 terminal seta, proximal 2 terminal setae curved proximally; coxal endite with 2 setae, epipodite with 5 setae; proximal basal endite with 2 setae; distal basal endite with 2 setae; endopod with 8 setae in groups of 2 + 6; exopodite with 3 setae.

Plate 4 issued from : E.L. Markhaseva & F.D. Ferrari in Invert. Zool., 2005, 2 (2). [p.136, Fig.15].
Female: A, P1 (anterior); B, left P1 (basis and endopod; anterior); C, right P1 (basis and endopod; anterior); D, P2 (posterior); E, P3 (posterior); F, P4 (posterior); G, right P5 (posterior); H, left P5 (exopod; posterior).
Scale bars: 0.1 mm.

Nota : P1 coxa without seta ; right basis with medial seta slightly curved, left without seta ; exopod 3-segmented ; right endopod with 2 medial and 2 terminal setae (unusual for Clausocalanoideans) ; left with 3 medial and 2 terminal setae ; Von Vaupel Klein’s organ, side, with basal seta slightly curved, anterior knob poorly developed without denticles. P5 3-segmented ; proximal and middle segments (coxa and basis) with denticles, distal segment with 1 short lateral seta, 1 long medial attenuation and 2 subterminal setae ; with denticles.

Plate 5 issued from : E.L. Markhaseva & F.D. Ferrari in Invert. Zool., 2005, 2 (2). [p.137, Table 2].
Byrathis volcani (Selected character states of species included in Byrathis gen. n.).
Ce = cephalosome; Mn = mandible; Pd = pediger segment; Ri = endopod; Re = exopod

Plate 6 issued from : E.L. Markhaseva & F.D. Ferrari in Invert. Zool., 2005, 2 (2). [p.138, Table 2 (contituing)].
Byrathis volcani (Selected character states of species included in Byrathis gen. n.).
Ri = endopod; Re = exopod.