Caecopilumnus loculatus sp. nov.

(Figs. 5J, 32, 33, 41D–F)

Material examined. Holotype: male (8.0 × 6.7 mm) (ZRC 2013.1723), station BMOO-15292, BIZ-589, intertidal, 0.5 m, west of entrance to Opunohu Bay, small beach with rocks, corals, rubble, exposed reef, 17.4968S 149.86306W, Moorea, Society Is., French Polynesia, coll. A. Anker & D. Ueno, 16 November 2010 . Paratypes: French Polynesia: 1 female (9.4 × 7.7 mm) (ZRC 2013.1724), station BMOO-15753, BIZ-626, reef flat with rocks and rubble, 0.5 m, south of Nihimaru, 17.4968S 149.905W, Moorea, Society Is., coll. A. Anker, 21 November 2010 ; 1 female (15.7 × 13.6 mm) (ZRC 2013.1725), station BMOO-16119, BIZ-677, sand flat, deep under rocks, 1 m, Motu I. channel, 17.4892S 149.91314W, Moorea, Society Is., coll. A. Anker, 2 December 2010 .

Diagnosis. Carapace subquadrate; dorsal surface finely granular; regions separated by shallow grooves (Fig. 32A). Anterolateral margin arcuate, hirsute, with 2 or 3 low, broad granuliform lobes (Fig. 32A). Merus of third maxilliped rounded (Figs. 5J, 33B). Merus of last ambulatory leg 2.0 times as long as broad; propodus as long as broad (Fig. 32A). Male abdomen relatively wide; a1 with lateral margins gently convex; a3–5 proportionately wide, a6 distinctly wider than long (Fig. 33A). Gl stout, sinuous, proximally dilated, distal half slightly more slender than proximal, tip narrow, lateral and mesial margin with row of spinules, mesial margin with several spinules medially (Fig. 33C–F). G2 slightly longer than G1, distal segment half length of basal segment (Fig. 33G).

Colour. In life, the body and pereopods are dirty white with pale brown patches on the dorsal surface of the carapace. The setae are brown (Fig. 41D–F).

Etymology. From the Latin loculatus for “box,” alluding to the quadrate box-like carapace characteristic of the species.

Remarks. Caecopilumnus loculatus sp. nov. most closely resembles C. crassipes in the form of the carapace (with low granulation and shallow grooves) and the shorter propodus of the last ambulatory leg. It differs from C. crassipes in its more quadrate carapace (Fig. 32A; Figs. 28A, 29A, 30 for C. crassipes), proportionately longer ambulatory meri (ratio for last leg 2.0, Fig. 32A; 1.5 for C. crassipes, Fig. 28A), proportionately wider male abdomen (Fig. 33A; Fig. 31A for C. crassipes), and the more sinuous G1 (Fig. 33C, D; Fig. 31D for C. crassipes). It can be separated from C. hirsutus by its shorter last ambulatory propodus (Fig. 32A; 27B, C for C. hirsutus), proportionately wider a6 (Fig. 33A; 27A for C. hirsutus), and the more sinuous G1 (Fig. 33C, D; Figs. 25C, 26C for C. hirsutus).

Distribution. Moorea (French Polynesia); 0.5– 1 m.