Eight new species of Charinus Simon, 1892 are described for the Brazilian Amazon, from the states of Pará (C. bichuetteae sp. n., C. bonaldoi sp. n., C. carajas sp. n., C. ferreus sp. n., C. guto sp. n. and C. orientalis sp. n.) and Amazonas (Charinus brescoviti sp. n. and C. ricardoi sp. n.). All new species can be differentiated from the other species of the genus by the number of pseudo-articles in basitibia IV, the presence/absence of median eyes, and the shape of the female gonopod. Brazil now becomes the country with the largest diversity of Amblypygi in the world, with 25 known species. Half of the new species described here have a high degree of endangerment: C. bichuetteae sp. n. is threatened by the flood caused by the hydroelectric dam of Belo Monte, and C. carajas sp. n., C. ferreus sp. n. and C. orientalis sp. n. are endangered by the iron mining in Carajás municipality and surroundings. The Charinus species here described are endemic to the Amazon Region, so in order to assure their preservation, it is strongly recommended a special care with their habitats (type localities) which are facing increasing rates of destruction and deforestation.

A new species of the genus Charinus Simon, 1892 is described from caves in the Rio Grande do Norte, Brazil. This is the first record of the genus for the state. This paper presents a map of the Charinus species distribution in Brazil with new records and a map of potential distribution of the genus in South and Central Americas. An updated key for Charinus species from Brazil is also presented.

The homology of three somatic systems in Schizomida is studied yielding the following results: (1) proposal of homology and chaetotaxy of abdominal setae in Surazomus; (2) revision of the cheliceral chaetotaxy in Schizomida, with suggestion of new homology scheme between Hubbardiidae and Protoschizomidae, description of a new group of setae in Hubbardiinae (G7), and division of setae group 5 in two subgroups, G5A and G5B; (3) proposal of segmental homology between trimerous and tetramerous female flagellum in Hubbardiinae with association of segment III of tri-segmented species to segments III + IV of tetra-segmented species. Considerations about the dorsal microsetae on the male flagellum are made. The genus Surazomus in Ecuador is revised. The sympatric species Surazomus palenque sp. nov. and S. kitu sp. nov. (Ecuador, Pichincha) are described and illustrated. The female of S. cuenca (Rowland and Reddell, 1979) is described, with two new distributional records for the species. Surazomus cumbalensis (Kraus, 1957) is recorded for the first time from Ecuador (Pichincha).