Taxonomic revision of the Neotropical spiders of the genus Idiops Perty, 1833 (Araneae, Idiopidae), with description of four new species Author Fonseca-Ferreira, Rafael 8E23FE6D-3D20-4667-9F69-15B132D9537B Pós-graduação em Ecologia, Evolução e Biodiversidade, Instituto de Biociências, Universidade Estadual Paulista, Avenida 24 A 1515, 13506 - 900 Rio Claro-SP, Brazil. rafaelbioferreira@gmail.com Author Guadanucci, José Paulo Leite D4955FF5-FE7F-4E68-AB2F-4A89593F9850 Departamento de Ecologia, Evolução e Biodiversidade, Instituto de Biociências, Universidade Estadual Paulista, Avenida 24 A 1515, 13506 - 900 Rio Claro-SP, Brazil. jose.guadanucci@unesp.br Author Yamamoto, Flávio Uemori 86719D83-2F02-4122-8CCE-D0932A3206D0 Laboratório de Coleções Zoológicas, Instituto Butantan, Av. Vital Brasil, 1500, Butantã, São Paulo, São Paulo, CEP 05503 - 900, Brazil. flayamamoto@gmail.com Author Brescovit, Antonio Domingos D5B81D79-AFAE-47B1-8A6E-DAB448A24BCC Laboratório de Coleções Zoológicas, Instituto Butantan, Av. Vital Brasil, 1500, Butantã, São Paulo, São Paulo, CEP 05503 - 900, Brazil. antonio.brescovit@butantan.gov.br text European Journal of Taxonomy 2021 2021-11-25 780 1 1 71 http://dx.doi.org/10.5852/ejt.2021.780.1581 journal article 3103 10.5852/ejt.2021.780.1581 41b8f51f-1d31-44c0-851e-2697e4e9497f 2118-9773 5761280 932663A6-D83D-49E0-B1F7-87F7DA8DC086 Idiops siolii (Bücherl, 1953) Figs 3B , 34 Pseudidiops siolli Bücherl, 1953: 126 , figs 6–8. Idiops siolii – Raven 1985: 158 . Diagnosis The female of Idiops siolii differs from that of other Neotropical species by having the spermathecae with ducts with a thickened median portion and mushroom-shaped receptacles ( Fig. 34C ). Type material Holotype BRAZIL – Pará • ♀ ; Belém , Campus do IAN - Embrapa Amazônia Oriental ; IBSP 3123 . Lost in the fire of 2010. Neotype (here designated) BRAZIL – Pará • ♀ ; Melgaço , Flona Caxiuanã , Estação Científica Ferreira Penna, Plote B; 1°47′32.3″ S , 51°26′2.5″ W ; 6–11 Apr. 2002 ; MPEG 1012 . Remark: The type specimen of Idiops siolii was lost in the 2010 IBSP fire. In accordance with the criteria of the ICZN Code ( ICZN 1999 ), a neotype is designated here, because the type is lost and the original description is inadequate to stabilise the species. The neotype is a specimen collected near the type locality, in the state of Pará, Brazil . Description Male Unknown. Female ( neotype MPEG 1012) HABITUS. See Fig. 34A . MEASUREMENTS. TBL 13.8, CL 7.6, CW 6.6, LL 1.1, LW 1.5, SL 4.4, SW 3.7. COLOR. Carapace and legs reddish brown, with yellowish coxae, reddish brown sternum ( Fig. 34A–B ). Abdomen gray. PROSOMA. Carapace and ocular arrangement as shown in Fig. 34A . Eye tubercle: 0.7 long; 1.4 wide. AME-ALE distance 1. Eye diameters: AME 0.21,ALE 0.5, PME 0.2, PLE 0.4. Thoracic fovea procurved. Labium with 3 cuspules ( Fig. 34B ). Maxilla with 31 cuspules, distributed throughout anterior ventral half ( Fig. 34B ). Basal segment of chelicerae with a prolateral row of 8 large teeth and 4 small retrolateral teeth, grouped in basal half; rastellum with 20–22 short spines of same size ( Fig. 34B ). Fig. 34. Idiops siolii (Bücherl, 1953) , ♀, neotype (MPEG 1012). A . Prosoma (dorsal view). B . Prosoma (ventral view). C . Genitalia (dorsal view). Scale bars = 1 mm. PALP AND LEG MEASUREMENTS. Palp = 12.5 (4.2, 2.7, 2.7, 2.9), I = 13.8 (4.5, 2.8, 3, 2.1, 1.4), II = 13.2 (4.3, 3, 2.5, 2, 1.4), III = 12 (4.1, 2.3, 2.8, 2, 0.8), IV = 18.4 (4.4, 3.9, 4, 3.6, 2.5). SPINATION. Palp: Ti p7-9-12, r6-10-10, Ta p12-10-11, r14-12-9. Leg I: Ti p3-7-10, r9-8-10, Mt p11-8-11, r3-9-8, Ta v0-0-3, p5-4-3, r5-5-4. Leg II: Pa p5-5-12, Ti v1-1-1, p2-4-6, r0-2-3, Mt v2-2-3, d2-2-2, p6- 4-2, r2-3-1, Ta v2-4-5, p0-2-5, r0-1-1. Leg III: Ti v1-1-0, r0-1-1, p2-6-7, Mt v2-2-4, p9-7-9, r2-2-2, Ta v0-0-3, p5-5-2, r1-0-0. Leg IV: Ti v0-0-1, Mt v0-1-2, p1-2-3, r0-1-1, Ta v2-1-2, p1-5-5, r0-2-2. SPERMATHECAE. V-shaped ducts with sclerotized portion between duct and receptacles. Bilobed ducts sclerotized, with evident granules ( Fig. 34C ). Distribution Brazil . Known only for the region of Belém and Melgaço (Pará), in the phytophysiognomies of the Amazonian region ( Fig. 3B )