Terrathelphusa mas n. sp.

(Figs. 9 A–H, 10A–E, 11I, J) Material examined. Holotype: male (35.5 × 26.4 mm) (ZRC 2015.0005), open green golf course, Borneo Highlands Resort, Gunung Penrissen, Kuching, Sarawak, 1O07’43.8”N 110O13’07.3”E, 852 m asl, coll. J. Grinang et al., 16 September 2013. Paratype: 2 females (larger 26.3 × 20.4 mm) (SBC.C.00374–75); 1 female (ZRC 2014.0840); data same as holotype.

Diagnosis. Carapace broader than long, conspicuously swollen, surface convex, smooth; cervical grooves broad, deep; epigastric cristae high, separated by deep epigastric groove; H-groove deep, long almost confluent with cervical grooves; epibranchial tooth indistinct but can be separated from external orbital angle by notch, anterolateral, frontal regions appearing compressed, supraorbital margin almost parallel with frontal margin; epistome median lobe blunt to bifurcated (Fig. 9 A–C). Male abdomen with elongated somite 6, lateral margins gently concave (Fig. 9 D). Third maxilliped ischium rectangular, about 2.1 times maximum width (Fig. 9 E). Ambulatory legs smooth, relatively slender, length about 4.4 times width (Fig. 9 F). Cheliped carpus rugose, without granules (Fig. 9 G, H), inner angle with narrower, acutely triangular tooth; gap between fingers of major chela conspicuously wide (Fig. 9 A). G1 distinctly curving outwards; terminal segment cone-shaped, tapered, gently curving upwards to tip, about 0.3 times length of subterminal segment (Fig. 10 A, B, D, E). Distal segment of G2 relatively long, about 0.8 times length of basal segment (Fig. 10 C).

Life colour. Body and appendages are bright golden yellow (Fig. 11 I, J).

Variation. The paratypes agree well with the holotype male except for variations in a few characters. In the larger specimens, the ambulatory legs are relatively longer and the cervical grooves are somewhat broader than in smaller specimens.

Habitat. The species is sympatric with T. aglaia n. sp., at high elevations on Gunung Penrissen, but it absent at low elevations.

Etymology. Derived from the Iban word mas for gold alluding to the golden appearance of the new species. The name is used as a noun in apposition.

Characters T. aglaia T. cerina T. kuchingensis T. kundong T. loxophthalma * T. mas T. ovis * T. telur* Third Length of ischium Length of ischium Length of ischium Length of Length of ischium Length of ischium Length of ischium Length of maxilliped about 1.9 times about 2.0 times about 1.8 times ischium about about 1.8 times about 2.1 times about 1.6 times ischium about

maximum width maximum width maximum width 1.9 times maximum width maximum width maximum width 1.5 times

maximum width maximum width Remarks. Terrathelphusa mas n. sp., can be distinguished from T. kuchingensis and the other species being described by a combination of characters: inner angle of carpus having a narrow and acutely triangular tooth (Fig. 9 A) (versus broad and acutely triangular tooth in T. kuchingensis (Fig. 1 A), T. aglaia n. sp. (Fig. 3 A) and T. cerina n. sp. (Fig. 5 A), and broadly triangular tooth in T. kundong n. sp. (Fig. 7 A); and the G1 is distinctly curving outwards (Fig. 10 A, B, C, D) (versus gently curving outwards in others, Figs. 2 A, B, D, E; 4A, B, D, E; 6A, B, D, E; 8A, B, D, E). Terrathelphusa species from the Kuching region differ from taxa in the northern region viz. T. loxophthalma, T. ovis and T. telur as summarised in Table 1.