Merizocera betong Li sp. nov. Figures 3, 4, 54

Type material.

Holotype: male (IZCAS), Ban Bo Nam Ron Village (5°49.96'N, 101°4.08'E, elevation 384 m), Betong District, Yala, Thailand, 24 October 2015, P. Wongprom leg. Paratypes: 1 male and 3 females (IZCAS), same data as holotype.

Etymology.

The specific name refers to the type locality; noun in apposition.

Diagnosis.

Males of M. betong sp. nov. resemble those of M. ranong sp. nov. and M. yuxi sp. nov., but can be distinguished by the smooth distally arising embolus (Fig. 3B) (vs. the crinkly distally arising embolus in M. ranong sp. nov. (Fig. 31B) and M. yuxi sp. nov. (Fig. 50B)), slender pyriform bulb (Fig. 3B) (vs. swollen pyriform bulb in M. ranong sp. nov. (Fig. 31B) and M. yuxi sp. nov. (Fig. 50B)), pointed embolus tip (Fig. 3B) (vs. lamina-like embolus tip in M. ranong sp. nov. (Fig. 31B) and flattened tip in M. yuxi sp. nov. (Fig. 50B)), embolus stalk 1/2 the length of tegular (Fig. 3B) (vs. embolus stalk 1/3 length of tegular in M. ranong sp. nov. (Fig. 31B), and similar in length in M. yuxi sp. nov. (Fig. 50B)), cymbial protrusion half the length of tegular in M. betong sp. nov. (Fig. 3D) and M. ranong sp. nov. (Fig. 31D) (vs. cymbial protrusion similar length with tegular in M. yuxi sp. nov. (Fig. 50D)). These species appear similar to those in the septentrionalis group of the genus Psiloderces, but can be distinguished by the more distinct cymbial protrusion (longer than the bulb or at least half the bulb’s length) (vs. cymbial protrusion inconspicuous or shorter than half the length of bulb in Psiloderces). The female can be distinguished by having two pairs of stalked spermathecae each bearing a globose distal part (Fig. 4A) (vs. one pair of posteriorly directed tubular spermathecae in M. ranong sp. nov. (Fig. 32A) and two pairs of tubular spermathecae in M. yuxi sp. nov. (Fig. 51A)).

Description.

Male (holotype). Total length 1.33; carapace 0.56 long, 0.51 wide; abdomen 0.71 long, 0.40 wide. Carapace circular, brownish, with dark brown marks laterally and dark brown median stripe (Fig. 4C). Fovea shallow. Thoracic region distinctly elevated medially. Clypeus, labium, and sternum dark brown. Abdomen slightly elongated, dark brown (Fig. 4E). Legs brown; measurements: I 6.85 (1.84, 0.19, 2.13, 1.86, 0.83), II 5.05 (1.38, 0.19, 1.53, 1.28, 0.67), III 3.79 (1.04, 0.18, 1.11, 0.94, 0.52), IV 5.50 (1.48, 0.18, 1.74, 1.42, 0.68). Palp (Fig. 3A-D): femur slender, three times longer than patella; patella not swollen; tibia half as long as femur; cymbium with distal protrusion, half as long as femur, length ratio of dorsal protrusion and cymbium 1.45; bulb pale yellow, pyriform with embolus arising distally; embolus stalk slightly bent with pointed embolus tip, embolus approx. half the length of tegular.

Female (paratype). General features and colouration similar to those of the male (Fig. 4D, E). Measurements: total length 1.52; carapace 0.61 long, 0.51 wide; abdomen 0.92 long, 0.48 wide. Leg measurements: I 5.09 (1.33, 0.17, 1.60, 1.28, 0.71), II 4.54 (1.23, 0.18, 1.34, 1.13, 0.66), III 3.46 (0.93, 0.18, 0.98, 0.86, 0.51), IV 5.11 (1.31, 0.19, 1.62, 1.28, 0.71). Epigastric area (Fig. 4B) with oval dark brown patch. Endogyne (Fig. 4A) with two pairs of stalked spermathecae, globose distally with medially curved receptacle.

Distribution.

Known only from the type locality (Thailand; Fig. 54).