Planche 1 issued from : O. Tanaka & M. Omori in Publ. Sero Mar. Biol. Lab., 1992, 35 (4/5). [p.259, Fig.3].
Male (from Izu region): a, forehead (lateral); b, last thoracic segments and urosome (lateral left side); c, urosome ((dorsal); d, rostrum (frontal view); e, A2; f, Md (mandibular palp); g, Md (cutting edge); h, Mx1; i, Mx2; j, Mxp; k, P1 (posterior); l, P2; m, P5; n, distal part of right P5; o, distal part of left P5.

Nota:
Rostrum consist of a plate with stout rami, each of which is followed by a small projection at apex.
A1 extends to end of first urosomal segment.
Mx1 reduced: 7 setae on outer lobe; 9 on exopod, 5 on basis, 3+6 on endopod, and 4 on 3rd and 2 on 2nd inner lobe; first inner lobe large but only armed with few small setae.
Mx2 reduced: 4th and 5th lobes each armed with a large claw-like spiniform seta; endopod with 8 weak sensory filaments of which one is slender and longer than others.
Prosome/Urosome lengths ratio 77 : 23.
Cephalosome and 1st metasomal segment separated, 4th and 5th incompletely separated by a line of demarcation. Urosomal segments without spinules and caudal rami in the proportional lengths 16 : 33 : 26 : 15 : 4 : 6 = 100.
P5, the right leg 3-segmented; distal segment armed with 2 spines; left leg 5-segmented and long; 1st to 4th segments about equal in length; 5th segment short, and with 1 distal and 1 lateral spine and patches of hairs.

Planche 2 issued from : O. Tanaka & M. Omori in Publ. Sero Mar. Biol. Lab., 1992, 35 (4/5). [p.257, Fig.2].
Female (from Izu region): d, urosome and caudal rami (dorsal); e, idem (lateral left side); f, Mx1; g, h, P5.

Nota: Prosome/urosome length ratio 74 : 26.
Forehead round with no trace of cephalic spine.
Urosome covered with spinules. Proportional lengths of segments and caudal rami 50 : 25 : 15 : 2 : 8 = 100.
Lateral margin of genital complex inflated; genital tubercle prominent.
Mx1: 9 setae on outer lobe, 10 on exiopod, 5 on basis, 10 on endopod, 4 on 3rd, 2 on 2nd and 10 on 1st inner lobe.
P5 very small, 3-segmented; 2nd segment longer than the 3rd; there is a faint line of demarcation near the proximal 1/3 of 3rd segment; 3rd segment armed with a large inner terminal spine and small outer spine (although the inner terminal spine not developed well in another specimen).

Planche 3 Issued from : K.A. Brodskii in Calanoida of the Far Eastern Seas and Polar Basin of the USSR. Opred. Fauna SSSR, 1950, 35 (Israel Program for Scientific Translations, Jerusalem, 1967) [p.237, Fig.148].
Female (from NW Pacif.): habitus (dorsal and lateral right side); Mp1, Mx2; Mp2, Mxp; S1, P1; S3, P3; S5, P5.
Nota: P5 slightly asymmetrical in size and form.
A specimen from the Pacific shows the following differences in comparison with those described from the Bay of Bengal: Head less rounded, spines of Mxp larger. The Pacific form possibly represents a separate variety.

Planche 4 issued from : R.B.S. Sewell in Mem. Indian Mus., 1929, X. [p.180, Fig.66].
Female (from off SE Sri-Lanka): a, posterior thoracic margin and urosome (lateral left side); b, anal segment and furcal ramus (lateral): c, Mx2; d, Mxp; e, P2; f, P4; g, P5.

Planche 5 issued from : O. Tanaka & M. Omori in Publ. Sero Mar. Biol. Lab., 1992, 35 (4/5). [p. 260].
Male: Proportional lengths of segments of A1.