A new cave-dwelling species of Charinus (Amblypygi: Charinidae) from northern Brazil.

We present the description and illustration of a new species within the genus Charinus Simon, 1892, discovered in a cave located in the state of Tocantins, situated in the northern region of Brazil. Charinus tocantinensis sp. nov., can be distinguished from its congeners by the following combination of distinctive characters: pedipalp femur with four dorsal spines and four ventral spines; well-developed median eyes and median ocular tubercle; female gonopods sucker-like, slightly longer than wide, opening rounded and margins with fold with each a small posterior slit; cheliceral claw with ten denticles. In addition to the species description, we have included a key for identifying Charinus species in Brazil, along with a distribution map that highlights the known species in the country. This newly described species marks the first formal documentation of a Charinus species within the state of Tocantins. With the addition of this species, the global tally of recognized Charinus species now stands at 98, and Brazil, in particular, is home to a total of 44 formally described species within this genus.

The flattie spiders of the Selenops isopodus/ species group (Araneae: Selenopidae) with a review of Selenops/ records from Colombia.

Here we examine the species of the Selenops isopodus species group: S. isopodus Mello-Leitão, 1941, S. arikok Crews, 2011, and S. curazao Alayón, 2001. We describe the female and male of S. bullerengue sp. nov. from Colombia and synonymize S. marilus Corronca, 1998a with S. isopodus, providing diagnoses and complete descriptions of both sexes of S. isopodus. Detailed images and a key to species in the group are provided. The distribution of all selenopid species in Colombia is reviewed using published records, museum specimens, and citizen science data from inaturalist.org.

Six new species of the spider genus Centroctenus Mello-Leitão from the Neotropical region (Ctenidae, Cteninae).

The species of the genus Centroctenus can be distinguished from other Ctenidae genera by the presence of a long tibiae and the absence of a retrolateral projection of the cymbium in the male palp, and by the presence of a rounded spermathecae in the female epigynum. The composition of this spider genus is herein expanded to eleven Neotropical species, with the description of six new species: Centroctenus dourados sp. n., C. claudia sp. n., C. chalkidisi sp. n., and C. varzea sp. n., from Brazil; and Centroctenus coloso sp. n. from Colombia and Centroctenus alinahui sp. n. from Ecuador. A map with the distribution of all known species in the genus is presented.

Six new species of the spider genus Centroctenus Mello-Leitão from the Neotropical region (Ctenidae, Cteninae)

The species of the genus Centroctenus can be distinguished from other Ctenidae genera by the presence of a long tibiae and the absence of a retrolateral projection of the cymbium in the male palp, and by the presence of a rounded spermathecae in the female epigynum. The composition of this spider genus is herein expanded to eleven Neotropical species, with the description of six new species: Centroctenus dourados sp. n., C. claudia sp. n., C. chalkidisi sp. n., and C. varzea sp. n., from Brazil; and Centroctenus coloso sp. n. from Colombia and Centroctenus alinahui sp. n. from Ecuador. A map with the distribution of all known species in the genus is presented.

Tenebriochernes, a new genus and species of Chernetidae (Arachnida: Pseudoscorpiones) from north-western Colombia, with ecological observationsp>.

A new pseudoscorpion genus, Tenebriochernes n. gen., with the type species T. concavus n. sp. is described from two caves in northern Colombia, where it inhabits the dark zone of caves. Two additional new species T. mohani n. sp. and T. pilosus n. sp., are described from conserved dry forest areas and buffer zones. Sexual dimorphism of the pedipalps is evident, particularly in the length of appendages and the width of the hand. The new genus shows affinities with the genus Neoallochernes Hoff, 1947. A taxonomic key, distribution map and ecological comments are given.

Charinus rocamadre (Amblypygi, Charinidae): description of the female, ultrastructure of the male and female gonopods, and mitochondrial DNA sequences.

Charinus rocamadre is the only species described and recorded from Colombia. It is know from only one male specimen collected from a cave in the Colombian Caribbean region. Herein, we describe the female of C. rocamadre for the first time, based on several specimens collected from the type locality of this species. We also provide images and describe the ultrastructure of male and female gonopods, as well as provide partial sequences of two mitochondrial genes (COI and 16S rRNA).