Sparianthis matupiri Casas & Rheims, 2024, spec. nov.

Sparianthis matupiri spec. nov. Figs 10A–E, 11A–D, 20 Type material: Holotype: ♂, BRAZIL: Amazonas: Manicoré, Barreira do Matupiri [05º32’S, 61º15’W], 18 May 1996, Equipe IBSP/SMNK leg. (IBSP 8877). Etymology. The specific name refers to the type locality; noun in apposition. Diagnosis. Males of S. matupiri spec. nov. resemble those of S. picta (Rheims 2020: figs 122–124) by the palps with strong, medial-retrolateral modified spine, a short embolus, with ventral hyaline membrane, TBC with retrolateral part protruding distally at retrolateral end and MA elongate and slender. They are distinguished from those of the latter species by the modified spine robust with truncated tip and TBE with apical projection long and slender, more than four times longer than wide (Figs 10 C–E; 11A–D) (spine with slender, pointed tip and TBE with apical projection widened and twisted in S. picta). Females are unknown. Description. Male (holotype): Prosoma brownish orange, slightly darker at eye area and along thoracic striae, with faint reticulated brown pattern on lateral margins of thoracic region; fovea brown; eye borders black; chelicerae slightly darker than prosoma, each with pair of longitudinal brown stripes; legs and pedipalps pale orange brown; labium brown, distally orange brown; endites pale yellow, distally cream colored; sternum pale yellow with darker margins; opisthosoma pale brownish yellow; dorsally with few irregular brown marks, in transversal rows in posterior half, largest around cardiac mark; ventrally with median V-shaped darker region on anterior half; spinnerets pale yellowish cream colored (Figs 10A–B). Total length 6.1. Prosoma: 2.6 long, 2.4 wide. Opisthosoma: 3.4 long, 1.5 wide. Eyes: diameters: 0.22, 0.15, 0.11, 0.15; interdistances: 0.15, 0.04, 0.30, 0.17, 0.12, 0.05. Legs (2143): I: 9.9 (2.8, 1.3, 2.6, 2.6, 0.6); II: 10.5 (3.1, 1.3, 2.7, 2.7, 0.7); III: 8.4 (2.5, 1.0, 2.3, 2.8, 0.9). Spination follows the generic pattern except tibiae I–II: d0-1-0; metatarsi I–II: v2-2-2-2; metatarsus III: p1-1-1; r1-1-1; v2-2- 1p. Palp: tibia short, less than half cymbium length, with three long prolateral spines (tips surpassing the proximal margin of the alveolus); dRTA concave with laminar triangular projection at base (best seen in ventral view); vRTA as a rounded triangle, close to dRTA (see Fig. 10E); ST visible retrolaterally, between 4:00–6:00 o’clock; MA slightly over 2.5 times longer than wide (Figs 10C–E, 11 AD). Female: Unknown. Distribution. Only known from the type locality (Fig. 20).