Issued from : R.B. Seymour Sewell in
Scient. Rep. John Murray Exped., 1947, 8 (1). [p.244, Fig. 67].
Male (from Arabian Sea): A, A1 of left side; B, A2; C, Md palp and base of biting ramus of right side; D, curved process on posterior lip of mouth; E, Mx1; F, Mx2; G, P1; H, P3; I, right P5; J, left P5.
Nota: - The posterior thoracic segment ixs produced backwards in a wing, the apex of which is rounded and bears a minute hair or seta.
- A2 : the proportional lengths of the exopod and endopod are as 53 to 47.
- Md asymmetrical; on the right side the biting ramus is produced on its anterior,aspect in a long curved tooth, similar to that in the female H. attenuatus
; in association with this tooth there is a curved tongue-like process from the lateral lip of the mouth on the right side. Sars (1925, Pl CXVI, fig.8) has described and figured a similar projection in H. attenuatus
, but he states that it situated on the left side (probably an error, fot it seems that the hook-like tooth on the mandible and the palp-like process are in apposition with each other). In the left Md the biting ramus (= gnathobase) bears a series of 5 teeth and 1 seta; the 1st tooth is simple; the 2nd is bifid but has a straight posterior margin; the 3rd, 4th and 5th are bifid atb their extremities and their posterior edges are armed with a row of spines. The basal segment of the palp bears 1 seta; the endopod arises from the segment considerably distal to the origin of the exopod (as in H. acutilobatus
- Mx1 closely resembles that of the female of H. acutilobus
except that the seta arising from the 2nd outer lobe is small.
- Mx2 with the 1st lobe bearing 2 groups of setae; in the 1st group are 2 setae, the distal of which is minute; in the 2nd group are 4 setae, of which the 1st is much smaller than the others. The 2nd lobe bears 1 seta. The 3rd lobe has 2, and the 4th lobe, 3 setae. The 5th lobe bears 6 setae, of which 4 are serrated, and the 6th is a stout curved spine with a few teeth on its margin. The 1st and 2nd segments of the endopod bear 2 setae, 1 short and curvee and the other straight; both are serrated along one margin. The 3rd segment bears 3 straight, serrated setae.
- Mxp resemble that of H. acutilobus
- P1 endopod 3-segmented, whereas in the females of both H. attenuatus
and H. acutilobus
there are only 2. Sars neither describes nor figures P1 in the male of H. acutilobus
, but, as he makes no mention of any difference, it is to be presumed that in that species the endopod resembles that of the female and is composed of 2 segments only.
- P2 to P4, both rami composed of 3 segments. The 3rd segment of the exopod shows a slight difference from the condition seen in H. acutilobus
female. The distal marginal spine, instead of being situated at the external distal angle, arises from the outer margin at a point about 1/3 the length of the segment. The external marginal spines arising from exopod 1 and 2 are much longer than in H. acutilobus
- P5 symmetrical; exopod composed of 3 segments, of which the 1st and 2nd each bear 1 marginal spine and the 3rd segment bears 2 marginal spines and 1 terminal spine.. There are no setae on the inner margin of any of the segment. The endopod is composed from 3 segments, of which the 1st and 2nd are devoid of a seta and the 3rd segment bears 4 setae.