Ischnothyreus marggii Richard, sp. nov.

(Figs. 53–55)

Type material. Holotype: male (PBI_OON00052394), SUMATRA: E. Sumatra, Bohorok, riverside, February 12, 1983, Coll. Deeleman, NNM Leiden.

Paratype: 1 male (PBI_OON00031844), collected with holotype.

Etymology. The species epithet is dedicated to Dr. Werner Marggi, a NMBE entomologist and specialist of European Carabidae.

Diagnosis. Males of I. marggii sp. nov. resemble males of I. narutomii (Nakatsudi, 1942) in palpal morphology but I. marggii sp. nov. possesses a conspicuous cheliceral fang process (p, Figs. 55 C, D) which is lacking in I. narutomii (Nakatsudi, 1942). Also the dorsal abdominal scutum is shorter and less sclerotized in I. marggii sp. nov. (Fig. 53 A, F). The retrolateral lobe of the palp is pointed and the tip of the bulb bears characteristic apical double membranes and a distal appendage (rl, adm, da, Figs. 54 D–G). The bulb has two pointed ventral protuberances (Fig. 54 F).

Description. Male: (PBI_OON00052394). Total length 1.54; carapace length: 0.80; carapace width: 0.66; abdomen length; 0.73.

CEPHALOTHORAX: Carapace yellow, broadly oval in dorsal view, pars cephalica strongly elevated in lateral view, anteriorly narrowed to 0.49 times its maximum width or less, surface of elevated portion of pars cephalica smooth, sides smooth; lateral margin straight, smooth; non-marginal pars thoracica setae dark, needlelike. Clypeus margin unmodified, straight in frontal view, sloping forward in lateral view, high, ALE separated from edge of carapace by their radius or more. Eyes six, well developed, all subequal, ALE oval, PME squared, PLE oval; posterior eye row recurved from above, procurved from front; ALE touching, ALE-PLE touching, PME touching throughout most of their length, PLE-PME touching. Sternum as long as wide, yellow, uniform, surface smooth, microsculpture absent, lateral margin without infra-coxal grooves, distance between coxae approximately equal, extensions of pre-coxal triangles absent, lateral margins unmodified; setae dark, needle-like, evenly scattered, originating from surface. Mouthparts: Chelicerae, endites and labium pale orange. Chelicerae straight, anterior face unmodified; directed medially, shape normal, with double process (p, Figs. 55 C, D), tip unmodified; setae dark, needle-like, evenly scattered. Labium elongated hexagon, anterior margin not indented at middle, same as sternum in sclerotization; with setae. Endites distally not excavated, anteromedian tip with one strong, tooth-like projection, much more heavily sclerotized than sternum.

ABDOMEN: ovoid, pointed posteriorly; dorsum soft portions yellow, without color pattern. Posterior spiracles not connected by groove. Scutum extending far dorsal of pedicel. Dorsal scutum weakly sclerotized, yellow, without color pattern, covering less than 1/2 of abdomen, between 1/4 and 1/2 abdomen width, fused to epigastric scutum, middle surface smooth, sides smooth. Epigastric scutum weakly sclerotized, surrounding pedicel, not protruding, small lateral sclerites absent. Postepigastric scutum weakly sclerotized, yellow, short, only around epigastric furrow, fused to epigastric scutum, anterior margin unmodified. Dorsum setae present, dark, needle-like. Spinneret scutum with fringe of needle-like setae.

LEGS: yellow, without color pattern; patella plus tibia I shorter than carapace. Leg spination: femora: I p0-1-1; II p0-0-1; tibiae: I, II p2-2-0; r2-2-0; metatarsi: I, II p1-1-0; r1-1-0.

GENITALIA: Epigastric region with sperm pore large, oval, situated at level of anterior spiracles, unmodified. Bulb with two small ventral protuberances, retrolateral lobe pointed (rl, Figs. 54 C–G). Tip of bulb short, blunt, with distal appendage and apical double membranes (da, adm, Figs. 54 D–G).

Female: Unknown.

Distribution. Known only from Bohorok in north-western Sumatra.