(Žgures 40–47)
Otostigmus pamuanus Chamberlin, 1920: 15.
Otostigmus (O.) pamuanus: Attems, 1930: 145.
Material examined
Holotype labelled Otostigmus pamuanus Ch. Type MCZ 2112. Solomons, Pamua (W. M. Mann).
Description
(Chamberlin’s data in parentheses where appropriate). Length 39 mm. Colour, after 70 years preservation, dark brown with black pigmentation beneath the cuticle (Žgure 43). Cuticle with a metallic sheen (deep olive with legs more greenish).
Antennomeres 25 on the left (Žgure 40) but one or more antennomeres are missing. Nineteen on the right which is regenerated (24). The basal two or two and a quarter antennomeres glabrous (2.3).
Forcipular coxosternal tooth plates with one outer and three inner principal teeth on each side, the outer with a low subsidiary tooth giving 51 5 (Žgure 41) (three large teeth of which the median and outer one are weakly incised or subdivided...). Process of forcipular femoroid with two inner teeth (Žgure 42).
Tergites marginate from 7 (9) with paramedian sutures complete from 5. With well-developed attened median ridge from 6 to 21. Lateral regions of tergite not corrugate (one or two lateral keels on each side more or less obscurely indicated). Small ridge-like spines present from 12 to 21. Tergite 21 with spines acute and very small: a well-marked longitudinal pit in posterior third (Žgure 44).
Incomplete paramedian sutures occupying anterior 50% of sternite 9 and as far as 66% on posterior sternites (...a few in anterior part of posterior region have the sulci extending to middle or entirely across plate). A slight posterior median pit on sternites 11–19 (Žgure 45) and spines similar to those of the tergites on 7–20 (not mentioned by Chamberlin). Last sternite with lateral margins converging only slightly and posterior margin slightly incurved (Žgure 46).