The type species of the Neotropical Actinopus, A. tarsalis Perty, 1833, is redescribed based on material from the type locality, the state of Piauí, Brazil. The species appears to be restricted to northeastern Brazil and is newly recorded from the state of Sergipe. An old record from the state of Rio Grande do Sul is rejected. Actinopus tarsalis differs from other species of the genus by details of the male copulatory bulb: tegular apophysis absent, robust embolar base, inserted basally at a right angle (90°); embolar apices apex flattened and expanded, arrow-shaped in dorsal view

We propose the name Bumba as a new name for Maraca, preoccupied by Maraca Hebard, 1926 (Orthoptera). We describe and illustrate Bumba lennoni, a new theraphosid species from Caxiuanã, Pará, Brazil. This species differs from the other species of the genus in the extremely reduced keel on male palpal organ and in the higher number of labial and maxillary cuspules. Females additionally differ in the spermathecal morphology. As a consequence of the name replacement, three new combinations are established.

Four new species of the Mouse Spider genus Missulena Walckenaer, 1805 (family Actinopodidae) are described from Western Australia based on morphological features of adult males. Missulena leniae sp. n.(from the Carnarvon and Yalgoo biogeographic regions), Missulena mainae sp. n. (Carnarvon), Missulena melissae sp. n. (Pilbara) and Missulena pinguipes sp. n. (Mallee) represent a broad spectrum of morphological diversity found in this genus and differ from other congeners by details of the male copulatory bulb, colour patterns, eye sizes, leg morphology and leg spination. Two of the species, M. pinguipes sp. n. and M. mainae sp. n., are characterised by swollen metatarsi of the fourth legs in males, a feature not previously recorded in the family. A key to males of all named Missulena species from Australia is presented and allows their identification based on external morphology.

A new genus Ami Pérez-Miles is proposed for six new species: A. caxiuana Pérez-Miles, Miglio & Bonaldo, from Caxiuanã National Forest, Pará, Brasil, the type species; A. yupanquii Pérez-Miles, Gabriel & Gallon, from the area of Puyo, Equador; A. bladesi Pérez-Miles, Gabriel & Gallon, from Isla Colón, Panamá; A. pijaos Jimenez & Bertani, from Ibagué, Tolima, Colombia; A. amazonica Jimenez & Bertani, from Leticia, Amazonas, Colombia; and A. weinmanni PérezMiles, from La Azulita, Apure, Venezuela. Avicularia obscura (Ausserer 1875) is transferred to Ami and re-diagnosed. Diagnostic characters of Ami are the modification of Type I urticating hairs, with unusually longer area b, and one or two subconical processes on retrolateral face of male palpal tibiae. Females of Ami differ further from those of other theraphosid genera by their highly characteristic spermathecae: paired ventral receptacles attached to an almost discrete, semicircular, sclerotized back-plate.

Actinopus Perty, 1833 is characterized and redescribed, including 80 species occurring from Panama to Argentina. Eighteen previously known species are redescribed: A. rufipes (Lucas, 1834); A. longipalpis C. L. Koch, 1842; A. nattereri (Doleschall, 1871); A. crassipes (Keyserling, 1891); A. robustus (O. Pickard-Cambridge, 1892); A. wallacei F. O. P.-Cambridge, 1896; A. princeps Chamberlin, 1917; A. xenus Chamberlin, 1917; A. fractus Mello-Leitão, 1920; A. paranensis Mello-Leitão, 1920; A. pusillus Mello-Leitão, 1920; A. dubiomaculatus Mello-Leitão, 1923; A. trinotatus Mello-Leitão, 1938; A. cucutaensis Mello-Leitão, 1941; A. echinus Mello-Leitão, 1949; A. clavero Ríos-Tamayo & Goloboff, 2018; A. gerschiapelliarum Ríos-Tamayo & Goloboff, 2018; and A. palmar Ríos-Tamayo & Goloboff, 2018. Additionally, A. tarsalis Perty, 1833, the type species, A. insignis (Holmberg, 1881) and other 18 species recently described species from Argentina and Bolivia, are re-evaluated. Forty-two new species are described: Actinopus castelo sp. nov., A. apalai sp. nov., A. mairinquensis sp. nov., A. obidos sp. nov., A. buritiensis sp. nov., A. pinhao sp. nov., A. ducke sp. nov., A. hirsutus sp. nov., A. jaboticatubas sp. nov., A. confusus sp. nov., A. pampulha sp. nov., A. candango sp. nov., A. paraitinga sp. nov., A. cornelli sp. nov., A. vilhena sp. nov., A. harveyi sp. nov., A. itapitocai sp. nov., A. ipioca sp. nov., A. itaqui sp. nov., A. xingu sp. nov., A. mesa sp. nov., A. caxiuana sp. nov., A. utinga sp. nov., A. emas sp. nov., A. bocaina sp. nov., A. osbournei sp. nov., A. dioi sp. nov., A. tutu sp. nov., A. azaghal sp. nov., A. itacolomi sp. nov., A. parafundulus sp. nov., A. urucui sp. nov., A. reznori sp. nov., A. anselmoi sp. nov., A. guajara sp. nov., A. apiacas sp. nov., A. jamari sp. nov. from Brazil; A. laventana sp. nov. from Argentina and Uruguay; A. lomalinda sp. nov. from British Guiana and Colombia; A. concinnus sp. nov. from Venezuela and Brazil; A. pindapoy sp. nov. from Argentina; A. panguana sp. nov. from Peru. The females of A. dubiomaculatus and A. cucutaensis and the males of A. nattereri are described for the first time. New records are presented for A. clavero; A.crassipes; A. dubiomaculatus; A. fractus; A. gerschiapelliarum; A. nattereri; A. palmar; A. paranensis; A. princeps, A. pusillus, A. robustus and A. wallacei. Ten old species names are herein considered species inquirendae: A. caraiba (Simon, 1889); A. harti Pocock, 1895; A. liodon (Ausserer, 1875); A. nigripes (Lucas, 1834); A. pertyi Lucas, 1843; A. piceus (Ausserer, 1871); A. rojasi (Simon, 1889); A. rufibarbis Mello-Leitão, 1930; A. scalops (Simon, 1889) and A. valencianus (Simon, 1889). Most species presently recognized were included in 11 informal groups based mainly on male palpal characters. A key for these groups plus three species, not included in any group, but known from males, is presented.