Currently, nine species of Syntrechalea F.O. Pickard-Cambridge, 1902 are known, six of them occurring in Brazil. In this study, two new species of of this genus are described and illustrated from the states of Amazonas and Tocantins, northern Brazil. Syntrechalea neblina sp.nov. can be distinguished from all known species by the bifurcated guide of the median apophysis. Syntrechalea robusta sp.nov. can be distinguished from all known species by the wider and concave ectal division of the retrolateral tibial apophysis. Additionally, new records of S. adis Carico, 2008, S. brasilia Carico, 2008, S. caporiacco Carico, 2008, S. napoensis Carico, 2008, S. syntrechaloides (Mello-Leitão, 1941) and S. tenuis F.O. Pickard-Cambridge, 1902 are provided.

The male of Dossenus guapore Silva, Lise & Carico, 2007 is described and illustrated for the first time, based on material from Bonito, Mato Grosso do Sul, Brazil. The spider genus Dossenus Simon, 1898 is distributed from Panama to southern Brazil and can be distinguished by the other known genera of Trechaleidae by the median dark brown band on the carapace that extends to the abdomen and by the spoon-like shape of the median apophysis of the male palpus. A new species of Dyrines Simon, 1903, D. brescoviti sp. nov., is described and illustrated based on material collected in Sergipe and Paraná, Brazil. The representatives of this spider genus are relatively small and can be distinguished from the other genera by the longitudinal dark brown bands on the legs. New records of Dyrines striatipes (Simon, 1898) are presented.

Neste trabalho são descritas e ilustradas quatro espécies novas do gênero Cybaeodamus Mello-Leitão, 1938: C. meridionalis sp. nov. do Brasil e Argentina, C. taim sp. nov. do Brasil, Argentina e Uruguai, C. brescoviti sp. nov. e C. tocantins sp. nov. do Brasil setentrional. Para as espécies Cybaeodamus enigmaticus (Mello-Leitão, 1939), C. lycosoides (Nicolet, 1849) e C. ornatus Mello-Leitão, 1938 são apresentadas novas ilustrações a partir do exame do material-tipo. As espécies Cybaeodamus nigrovittatus Mello-Leitão, 1941 cujo holótipo é um indivíduo jovem, C. pallidus (Mello-Leitão, 1943) da qual o tipo não foi localizado, C. rastellifer (Mello-Leitão, 1940) e C. scottae Mello-Leitão, 1941, ambas com tipos juvenis, todas da Argentina, são consideradas species inquirendae.

Four new species of the spider genus Cybaeodamus Mello-Leitão, 1938 are described and illustrated: C. meridionalis sp. nov. from Brazil and Argentina, C. taim sp. nov. from Brazil, Argentina and Uruguay, C. brescoviti sp. nov. and C. tocantins sp. nov. from setentrional region of Brazil. For the species Cybaeodamus enigmaticus (Mello-Leitão, 1939), C. lycosoides (Nicolet, 1849) and C. ornatus Mello-Leitão, 1938, new illustrations based on the examination of the types are presented. The species Cybaeodamus nigrovittatus Mello-Leitão, 1941 which the holotype is an immature specimen, C. pallidus (Mello-Leitão, 1943) which the type was not located, C. rastellifer (Mello-Leitão, 1940) and C. scottae Mello-Leitão, 1941, both described upon juvenile specimens, all from Argentina, are considered as species inquirendae.

Uma espécie nova do gênero Syntrechalea F.O.P.-Cambridge, 1902 é descrita e ilustrada, a partir de material coletado em Loreto Mocagua, Colômbia. Os representantes deste gênero apresentam o hábito arbóreo de forragear e são distinguidos dos demais gêneros de Trechaleidae pela carapaça achatada,pernas longas e metatarsos e tarsos flexíveis. Novos registros de distribuição de Syntrechalea tenuis F.O.P.-Cambridge, 1902 na Colômbia são apresentados.

A new species of the spider genus Syntrechalea F.O.P.-Cambridge, 1902 is described and illustrated based on material collected in Loreto Mocagua, Colombia. Representatives of this spider genus exhibit an arboreal foraging behavior and are distinguished from the other genera of Trechaleidae by the flattened carapace, long legs and flexible metatarsi and tarsi. New records on the distribution of Syntrechalea tenuis F.O.P.Cambridge, 1902 in Colombia are presented.

Naatlo Coddington, 1986 é diagnosticado pela presença de uma aba no epígino das fêmeas e o condutor reduzido e ápice do embolo mais complexo nos machos. Neste trabalho duas espécies novas do Brasil são descritas e ilustradas: N. serrana sp. nov. do Rio Grande do Sul e N. maturaca sp. nov. do Amazonas, Pará e Mato Grosso.

Naatlo Coddington, 1986 is diagnosed by the presence of the epigynal flap in the females and the reduced conductor and the more complex embolic tip in the males. In this paper it are described and illustrated two news species from Brazil: N. serrana sp. nov. from state of Rio Grande do Sul and N. maturaca sp. nov. from states of Amazonas, Pará and Mato Grosso.

Pseudattulus incertus Caporiacco, 1955 é sinonimizada com P. kratochvili Caporiacco, 1947 e o macho desta espécie é redescrito. O gênero Uspachus Galiano, 1995 é sinonimizado com Romitia Caporiacco, 1947 e o macho de sua espécie-tipo, R. nigra Caporiacco, 1947, é redescrito.As seguintes combinações novas são estabelecidas para as espécies até o momento incluídas em Uspachus: Romitia albipalpis (Taczanowski, 1878), Romitia andina (Taczanowski, 1878), Romitia bahiensis (Galiano, 1995), Romitia colombiana (Galiano, 1995), Romitia juquiaensis (Galiano, 1995), Romitia ministerialis (C.L. Koch, 1846), Romitia misionensis (Galiano, 1995) e Romitia patellaris (Galiano, 1995). O gênero Pseudamphidraus Caporiacco, 1947 é sinonimizado com Noegus Simon, 1900 pela transferência de sua espécie-tipo, Noegus niger (Caporiacco, 1947) comb. nov., cujo macho é redescrito. As espécies Pseudamphidraus variegatus Caporiacco, 1947 e Marma trifidocarinata Caporiacco, 1947 são sinonimizadas com Marma nigritarsis (Simon, 1900).

Pseudattulus incertus Caporiacco, 1955 is synonymized with P. kratochvili Caporiacco, 1947 and the male of this species is redescribed. The genus Uspachus Galiano, 1995 is synonymized with Romitia Caporiacco, 1947 and the male of its type species, R. nigra Caporiacco, 1947, is redescribed. The following new combinations are established for the species formerly included in Uspachus: Romitia albipalpis (Taczanowski, 1878), Romitia andina (Taczanowski, 1878), Romitia bahiensis (Galiano, 1995), Romitia colombiana (Galiano, 1995), Romitia juquiaensis (Galiano, 1995), Romitia ministerialis (C.L. Koch, 1846), Romitia misionensis (Galiano, 1995) and Romitia patellaris (Galiano, 1995). The genus Pseudamphidraus Caporiacco, 1947 is synonymized with Noegus Simon, 1900 by transfer of its type species, Noegus niger (Caporiacco, 1947) comb. nov., whose male is herein redescribed. The species Pseudamphidraus variegatus Caporiacco, 1947 and Marma trifidocarinata Caporiacco, 1947 are synonymized with Marma nigritarsis (Simon, 1900).