Pilumnopeus granulatus Balss, 1933

(Figures 2, 6C–D, 7A–D)

Pilumnopeus serratifrons granulatus Balss, 1933: 34 .

Heteropanope (Pilumnopeus) serratifrons granulatus — Serène 1968: 87.

Pilumnopeus granulatus — Takeda & Miyake 1969: 127 (part).— Ng et al. 2008: 141.

Material examined. Lectotype (herein designated): male (14.4 mm × 10.7 mm) (ZMH K-001550), Viti Levu, Fiji (labelled as ex. Mus, Godeffroy MG 2232), coll. no information.

Diagnosis. Dorsal carapace surface with regions well defined, with numerous rounded granules, especially dense on posterior half of carapace, with dense, low pubescence between the raised regions (Fig. 2A, B); frontal margin lined with prominent rounded granules (Fig. 2D); posterior margin of epistome distinctly wide with a low obtusely triangular median lobe (Fig. 2E); outer surfaces of cheliped covered with numerous flattened granules and short setae (Fig. 2G); male pleon proportionately wider, with somite 6 wider than long, rectangular (Fig. 6D); overall G1 relatively longer, relatively more slender (Fig. 7A); G1 distal part less strongly curved with tip not reaching main stem; distal inner margin with 8 distinctly recurved spines (Fig. 7A–C).

Remarks. Balss (1933: 34) named the taxon as a subspecies of P. serratifrons, noting that “Beide Tiere unterscheiden sich von den australischen Stücken durch ihre Scheren, welche auf der Aussenseite ziemlich stark granuliert sind, während bei den typischen Formen die Aussenseiten glatt sind und nur der Unterrand derselben granuliert ist.” [Both animals differ from the Australian specimens by their claws, which are quite strongly granulated on the outside, while in the typical forms the outside surfaces are smooth and only the lower edge is granulated.] Balss (1933) had two specimens, one male (14.0 mm × 11.0 mm) from Fiji and a smaller male (10.5 × 8.0 mm) from Great Harbour, in New Mecklenburg (= present day New Ireland Province), northeastern Papua New Guinea. Although the present specimen from Fiji is labelled as a “ holotype ”, it is not. Both of Balss’ (1933) original specimens are syntypes as he did not designate a holotype. The larger specimen, which is examined in the present study, is herein designated as the lectotype of Pilumnopeus serratifrons granulatus Balss, 1933 .

Pilumnopeus granulatus resembles P. serratifrons, but can readily be distinguished by the more strongly granulated dorsal carapace surface with dense, low pubescence between the raised regions (Fig. 2A, B) (versus surface less granulated, with more scattered setae in P. serratifrons; Fig. 1A, B); the frontal margin is lined with prominent rounded granules (Fig. 2D) (versus with sharp granules in P. serratifrons; Fig. 1D); the outer surfaces of the cheliped are covered with numerous flattened granules and very low setae (Fig. 2G) (versus with low granules and is generally smooth and glabrous in P. serratifrons; Fig. 1G); the male pleon is proportionately wider, with somite 6 wider than long and rectangular (Fig. 6D) (versus pleon narrower, with somite 6 as long as broad and quadrate in P. serratifrons; Fig. 6B); the overall G1 is relatively longer and more slender (Fig. 7A) (versus relatively shorter and stouter in P. serratifrons; cf. Davie 1989: fig. 5E); and the distal part of the G1 is less strongly curved with the tip not reaching the main stem (Fig. 7A–C) (versus tip longer and overlaps the main G1 stem in P. serratifrons; cf. Davie 1989: fig. 5E, F).

The strong granulation on the carapace and chelipeds of P. granulatus is somewhat similar to the condition in P. marginatus (Stimpson, 1858) . In P. granulatus, however, the granules on the dorsal carapace surface are more distinct, more raised and more widespread, and there is dense short pile-like pubescence between the raised regions (Fig. 2A, B) (versus the granules are lower, and the carapace lacks the pile-like pubescence but instead has numerous longer setae on P. marginatus; Fig. 5F). In addition, the frontal margin is lined with prominent rounded granules (Fig. 2C) (versus with low granules in P. marginatus; Fig. 5D); the outer surface of the third maxilliped has short pubescence (Fig. 2C) (versus surface is densely setose in P. marginatus; Fig. 5C); and the setae on the outer surfaces of the cheliped are low and visible only between the granules (Fig. 2G) (versus setae are overall distinctly denser and longer in P. marginatus; Fig. 5F).