Monatractides terpsichore, Pešić, Vladimir & Smit, Harry, 2014

Monatractides terpsichore n. sp.

( Figs. 34A–G View FIGURE 34 A – G , 35A–B View FIGURE 35 A – B , 37H View FIGURE 37 A – I , 38H View FIGURE 38 A – I )

Type series. Holotype female, dissected and slide mounted, Ghana, Plunge pool Agumatsa Falls, Agumatsa Wildlife Sanctuary, 7º 06.350 N, 0º 36.476 E, alt. 258 m asl., 22.ii.2013 Smit. Paratypes: one male, Nubui River, Agumatsa Wildlife Sanctuary, 7º 06.986 N, 0º 35.548 E, alt. 254 m asl., 22.ii.2013, Smit, dissected and slide mounted.

Diagnosis. P-2 longer than P-4, P-2 with long and slender ventral seta located away from distal edge, P-4 bowed, ventral margin with setae-bearing protrusion in the centre of the segment.

Description. General features —Idiosoma roundish; frontal platelets slightly shorter than shoulder platelets (shoulder/frontal platelets L ratio 1.05–1.07); frontal margin medially pointed, between anterolaterally orientated apodemes ( Fig. 34A View FIGURE 34 A – G ); Cxgl-4 located far anteriorly, near tip of Cx-I; gnathosomal bay deep U-shaped, proximally wide box-shaped; posterior suture line of Cx-IV strongly extending posteriorly beyond posterior margin of genital field, laterally curved; excretory pore and Vgl-2 away from the line of primary sclerotization, Vgl-2 posterior to excretory pore; gnathosoma nearly triangular in lateral view, with short, cone-shaped rostrum ( Fig. 34G View FIGURE 34 A – G ); P-2 longer than P-4, P-2 ventral margin straight or slightly concave, bearing long and slender ventral seta located away from distal edge, P-3 ventral margin concave, P-4 bowed, ventral margin with setae-bearing protrusion in the centre of the segment ( Figs. 34D–E View FIGURE 34 A – G , 35B View FIGURE 35 A – B ). Male: medial margin of Cx-II/III relatively short; genital field subrectangular. Female: genital field pentagonal.

Measurements. Female ( holotype)—Idiosoma (ventral view: Figs. 34C View FIGURE 34 A – G , 38H View FIGURE 38 A – I ) L 697, W 567; dorsal shield ( Figs. 34B View FIGURE 34 A – G , 37H View FIGURE 37 A – I ) L 588, W 478, L/W ratio 1.22; dorsal plate L 538; shoulder platelets L 141–144, W 64–69, L/W ratio 2.04–2.25; frontal platetelets L 131–134, W 71–72, L/W ratio 1.8–1.9; shoulder/frontal platelets L ratio 1.07. Gnathosomal bay L 147, Cx-I total L 256, Cx-I mL 109, Cx-II+III mL 27; ratio Cx-I L/Cx-II+III mL 9.6; Cx-I mL/ Cx-II+III mL 4.1. Genital field L/W 152/144, ratio 1.06; distance genital field-excretory pore 172, genital fieldcaudal idiosoma margin 261. Gnathosoma vL 167; chelicera total L 183–184, basal segment L 143–151, claw L 36–39, L basal segment/claw ratio 3.7–4.1; palp total L 203–204, dL/H, dL/H ratio: P-1, 28/24, 1.16; P-2, 63/ 41–42, 1.52; P-3, 40/33–34, 1.19; P-4, 51/23, 2.2; P-5, 21–22/11, 1.9; P-2/P-4 ratio 1.24; dL of I-L-2-6: 68, 74, 92, 99, 103; I-L-6 H 41–42, dL/H I-L-6 ratio 2.5.

Male ( paratype from Nubui river)—Idiosoma (ventral view: Fig. 35A View FIGURE 35 A – B ) L 589, W 456; dorsal shield L 494, W 406, L/W ratio 1.22; dorsal plate L 453; shoulder platelets L 128, W 61, L/W ratio 2.1; frontal platelets L 122, W 58–59, L/W ratio 2.0–2.1; shoulder/frontal platelets L ratio 1.05. Gnathosomal bay L 136, Cx-I total L 237, Cx-I mL 100, Cx-II+III mL 37.5; ratio Cx-I L/Cx-II+III mL 6.3; Cx-I mL/Cx-II+III mL 2.7. Genital field L/W 122/103, ratio 1.18; distance genital field-excretory pore 133, genital field-caudal idiosoma margin 192. Gnathosoma vL 147; chelicera total L 168; palp total L 182–183, dL/H, dL/H ratio: P-1, 25/22, 1.1; P-2, 55/42, 1.32; P-3, 35/32, 1.09; P-4, 46/21–22, 2.15; P-5, 21–22/11, 2.0; P-2/P-4 ratio 1.2; dL of I-L-2–6: 60, 68, 86, 92, 95–96; I-L-6 H 39–42, dL/H I-L-6 ratio 2.3–2.45.

Etymology. The species is named after Terpsichore (Ancient Greek: Τερψιχόρη), one of nine Muses from Greek mythology, who was a patron of dance. The species name is a noun in apposition (in the nominative case).

Discussion. The combination of a relatively short and bowed P-4 and the ventral seta on P-2 clearly shifted from the distal edge, separates the new species from other members of the genus. Due to the latter character, Monatractides ( M.) terpsichore n. sp. somehow resembles M. ( M.) divergens ( Cook, 1966) ( Liberia, Cook 1966), and M. ( M.) amota ( K.O. Viets, 1974) ( Congo, K.O. Viets & Böttger 1974), both characterized by the ventral seta on P-2 and P-3, respectively, shifted from the distal edge of the segment. The latter species is similar in the general shape of gnathosoma and chelicera (vs. gnathosoma with apically pointed, rostrum and chelicerae with a larger claw in M. ( M.) divergens , see Cook 1966) but can easily be distinguished by the relatively longer and slender P-4, without ventral tubercle (see K.O. Viets & Böttger 1974).

Remarks. The male ejaculatory complex was not found but sclerotized framework immediately above the genital field can be hardly visible.

Habitat. Plunge pool and a sandy/bouldary streams, shaded by forest.

Distribution. Ghana.