Revision of the Neotropical spider genus Acanthoctenus (Araneae: Ctenidae Acanthocteninae) Author Arizala, Stephany Instituto de Biologia, Universidade Estadual de Campinas, (PG-IB / UNICAMP), Bloco O CP- 6109. Av. Bertrand Russel s / n. CEP 13083 - 865 Campinas, SP, Brazil. Author Labarque, Facundo Martín 0000-0001-9413-1949 Departamento de Ecologia e Biologia Evolutiva (DEBE), Universidade Federal de São Carlos (UFSCar), Campus São Paulo. Rodovia Washington Luís, Km 235, CEP 13565 - 905 São Carlos, SP, Brazil. & facundo. labarque @ gmail. com; https: // orcid. org / 0000 - 0001 - 9413 - 1949 facundo.labarque@gmail.com Author Polotow, Daniele 0000-0002-1069-1808 Departamento de Ecologia e Biologia Evolutiva (DEBE), Universidade Federal de São Carlos (UFSCar), Campus São Paulo. Rodovia Washington Luís, Km 235, CEP 13565 - 905 São Carlos, SP, Brazil. & danielepolotow @ gmail. com; https: // orcid. org / 0000 - 0002 - 1069 - 1808 danielepolotow@gmail.com text Zootaxa 2021 2021-01-27 4920 1 1 55 journal article 8507 10.11646/zootaxa.4920.1.1 8cd8a768-c115-4b2e-8167-f9ae52eb4f80 1175-5326 4471454 89E38EAD-A8D2-4ED9-A7D0-8C388A785E61 Acanthoctenus chickeringi sp. nov. Figs 10A , 38–41 Type material. Female holotype from San Lorenzo , Fort Sherman , [ 9°21’45.4”N , 79°57’17.7”W ], Panama . 15.VIII.1939 , A.M. Chickering coll., deposited in MCZ ; 1 male paratype , same data as the holotype, MCZ ; 6 female paratypes , same data, MCZ . Etymology. The specific name is a patronym in honor of Arthur Chickering, in recognition to his many contributions to the knowledge of Panamanian spiders. FIGURE 38. Acanthoctenus chickeringi sp. nov. , male paratype (MCZ). A–C, habitus; A, dorsal; B, ventral; C, frontal. D–E, male palp; D, ventral; E, retrolateral. FIGURE 39. Acanthoctenus chickeringi sp. nov. , copulatory organs. A–B, male palp (paratype, MCZ); A, ventral; B, retrolateral. C–D, female genitalia (holotype, MCZ); C, epigynum, ventral; D, internal genitalia, dorsal. FIGURE 40. Acanthoctenus chickeringi sp. nov. , female holotype (MCZ). A–B, habitus; A, dorsal; B, ventral; C, frontal. D, epigynum, ventral. Other material examined. PANAMA . Canal Zone : Barro Colorado Island , [ 9°09’15.2”N , 79°50’46.1”W ], 1 female , VII.1954 , A.M. Chickering coll. ( MCZ ) ; same locality and collector, 1 female , VI .1950 ( MCZ ) ; same locality and collector, 1 female , VII.1950 ( MCZ ) ; same locality, 1 female , 30.XII.1935 , Griswold coll. ( MCZ ) ; France Field [ 9°20’53.2”N , 79°52’51.9”W ], 1 female , 8.XI.1939 , A.M. Chickering coll. ( MCZ ) . Diagnosis. Males of Acanthoctenus chickeringi sp. nov. ( Figs 38 D–E, 39A–B) resemble those of A. virginea stat. res., comb. nov. ( Figs 31 C–D, 32A–B) by the palpal tibia reduced, 1.5 times longer than wide. It can be distinguished by the RTA elongated, longer than wide, the embolus relatively wider, not bended basally, and palpal tibia not swollen basally. A. virginea stat. res., comb. nov. presents a short, wider than long RTA, a relatively thinner embolus, which is bended basally, and a basally swollen palpal tibia. Females of Acanthoctenus chickeringi sp. nov. ( Figs 39 C–D, 40D, 41) resemble those of A. spinipes ( Figs 16 C–D, 17C, 18A–B) by the atrium massive, subquadrangular, as wide as long. It can be distinguished by the lateral borders of the atrium slightly sclerotized, the median sector extending into the atrium, and the copulatory ducts S-shaped, bended apically. A. spinipes presents strongly sclerotized anterior and lateral borders of the atrium, no extension of the median sector into the atrium, and no apically bended copulatory ducts. Description. Male ( paratype MCZ). Total length 8.50. Carapace 4.37 long and 3.78 wide. Clypeus 0.23 high. Eye diameters: AME 0.28, ALE 0.21, PME 0.35, PLE 0.38. Leg measurements: I: femur 6.69/ patella 2.44/ tibia 7.86/ metatarsus 7.11/ tarsus1.93/ total 26.03; II: 5.25/ 2.26/ 5.75/ 4.71/ 1.35/ 19.32; III: 4.50/ 1.65/ 3.86/ 4.73/ 1.39/ 16.13; IV: 5.89/ 1.65/ 6.01/ 7.89/ 2.18/ 23.62. Leg formula 1423. Leg spination: tibia I, II v-2-2-2-2-2-2-2-2-2, p-1-1-0-1-1, r-1-0-1-1-1; III v-2-2-2, p-1-1-0-1, r-0-1-1-1, IV v-2-2-2, p-0-1-0-1, r-1-0-1; metatarsus I, II v2-2-2- 2-2, p-1-0-1-0, r-0-1-0-1, III v-2-2-2-2, p-1-1-0-1, r-0-1-1-1-1, IV v-2-2-2-2 p-1-0-1-1, r-1-1-1. Palp ( Figs 38 D–E, 39A–B): tibia shorter than cymbium; RTA with large base, elongated and with blunt apex; cymbium elongated and with retrobasal projection; embolus elongated, cylindrical, and bent; conductor hyaline and following the tip of embolus; median apophysis laminar, elongated, narrow at the base and wider at the apex, with a proapical hook and retrolateral ridge. Female ( holotype MCZ). Total length 9.81. Carapace 4.66 long and 3.84 wide. Clypeus 0.27 high. Eye diameters: AME 0.28, ALE 0.21, PME 0.39, PLE 0.42. Leg measurements: I: femur 5.18/ patella 2.19/ tibia 5.65/ metatarsus 4.52/ tarsus1.34/ total 18.88; II: 4.72/ 2.04/ 4.38/ 3.96/ 1.23/ 16.33 III: 3.94/ 1.66/ 3.16/ 3.57/ 1.23/ 13.56; IV: 4.78/ 1.63/ 4.24/ 5.17/ 1.74/ 17.56. Leg formula 1432. Leg spination: tibia I v-2-2-2-2-2-2-2-2-2, p-1-0-1-1-1, r- 1-1-1-1-1; II v-2-2-2-2-2-2-2, p-1-1-1, r-0-1-1-1-1-1, III v-2-2-2, p-0-1-1, r-0-1-1-1, IV v-2-2-2, p-0-1-1, r-0-1-1-1; metatarsus I v2-2-2-2, p-0-1-0, r-0-1, II v2-2-2-2-2, p-0-1-1, r-0-1, III v-2-2-2, p-1-1-1, r-0-1-1, IV v-2-2-2 p-0-1-1, r-0-1-1. Epigynum ( Figs 39 C–D, 40D, 41): median sector elongated, narrow anteriorly extending into the atrium, not projected posteriorly; anterior border of the lateral sectors slightly curved; atrium massive, subquadrangular; copulatory ducts bended apically, S-shaped; spermathecae head quote-shaped, with apical glandular openings, spermathecae base curled; fertilization ducts tubular, slanting outwards. Variation. Five females: total length 8.38–10.34, carapace length 3.99–4.59. Distribution. Panama ( Fig. 10A ).