Centroctenus chalkidisi sp. n.

Figure 8, 12C

Type material. Male holotype from COOMFLONA, Km 117, BR-163, Flona do Tapajós (3°31’1”S, 55°4’23”W), Belterra, Pará, Brazil, 15–17/XI/2018, Curso EBAM 2018 coll., deposited in IBSP 250630 .

Additional material examined. None.

Etymology. The specific name is a patronymic in honor to the Hipócrates Chalkidis, teacher and curator of the UNAMA collection, in the city of Santarém, Pará, Brazil.

Diagnosis. Centroctenus chalkidisi sp. n. resembles C. alinahui sp. n. by the shape of the copulatory bulb sclerites (Fig. 8 B–D), but can be distinguished by the cymbium with straight prolateral border, RTA distally flat and wide, with a scalloped internal branch and an acute external projection (Fig. 8 B–D).

Description. Male (holotype). Carapace orange, with cephalic area and lateral borders brown (Fig. 8A). Chelicerae, labium and endites orange. Legs and palps orange, with black bands on the tibia and metatarsus. Sternum yellow. Abdomen gray with an orange median dorsal folium (Fig. 8A), ventrally light gray. Total length 9.8. Carapace 5.4 long and 4.2 wide. Eye diameters: AME 0.14, ALE 0.10, PME 0.18, PLE 0.20. Chelicerae: promargin with 3 teeth, the median almost twice as high as the laterals; retromargin with 5 similar-sized teeth. Leg measurements: I: femur 9/ patella 3.3/ tibia 9.2/ metatarsus 8.6/ tarsus 3.2/ total 33.3; II: 8.6/ 3.3/ 8.1/ 7.8/ 2.8/ 30.6; III: 7/ 3.5/ 7.5/ 6.3/ 2.2/ 26.5; IV: 9.6/ 3/ 8.6/ 12.2/ 3/ 36.4. Leg formula: 4123. Leg spination: tibia I-II v2-2-2-2-2, r1-1-0, p1-1-0, III-IV v2-2-2, r1-1-0, p1-1-0; metatarsus I-II v2-2-2, r1-1-0, p1-1-0, IV v2-2-2, r1-1-1, p1-1-1. Palp (Fig. 8 B–D): tibia approximately two times the cymbium length; cymbium oval, distally tapered; tegulum oval; embolus short, curved, with large and long base; median apophysis enlarged; conductor hyaline next to the tip of embolus.

Female. Unknown.

Natural history. The specimen was collected manually at night, in a well-preserved area of dense ombrophilous forest in the Flona do Tapajós. This type of vegetation is characterized by the dominance of large trees under climatic regime of high temperatures and intense rainfall distributed throughout the year. The tree genera Hevea, Bertholletia and Dinizia predominate, with woody lianas, palms and epiphytes also abundant (Brazão & Santos 1997).

Distribution. Known only from the type locality (Fig. 12C).