Rhene formosa

Like many in the genus, Rhene formosa resembles a beetle.^[10] It is a small spider with a body is divided into two main parts: a cephalothorax and an abdomen.^[2] The male's carapace, the hard upper part of the cephalothorax, is typically 2.2 mm (0.087 in) in length, 2.1 mm (0.083 in) in width and 0.9 mm (0.035 in) in height. It is flat, dark brown and hairy, mostly covered with brown and grey hairs, but with a line of white hairs behind the first row of eyes. Its face, known as the clypeus, is very dark and low. Its chelicerae are dark brown with a single tooth at the back and two at the front. The spider's remaining mouthparts, including its labium and maxillae are brown.^[11]

The female's elongated abdomen is longer than its carapace, measuring 3.5 mm (0.14 in) in length and 2.3 mm (0.091 in) in width. The top of its abdomen is light beige and a vague brownish pattern that can be seen near the back. As well as a silver lustre, it has a scattering of brown hairs on it; these are particularly dense and long on the front edge. The bottom is light brown. It has brown spinnerets. The spider's legs are brownish; its front legs are longer, darker and thicker than the others and are marked with long hairs.^[11]

Rhene formosa has distinctive copulatory organs. It has a large epigyne, the external visible part of its copulatory organs, that shows pronounced sclerotization. It has a shallow depression in the middle and copulatory openings that are hidden in sclerotized basket-like features. The spider's insemination ducts are particularly long and thin.^[11] Compared to the related Rhene sororis, which shares its long thin insemination ducts, it has more sclerotization.^[12] It has smaller spermathecae, or receptacles, than the related Rhene obscura and Rhene pinguis and lacks the ridge in the middle of the central depression that is characteristic of the former species.^[13][14] The male has not been described.^[1]

Although Dendryphantine spiders a predominantly found in the Americas, Rhene spiders live in Africa and Eurasia.^[4] Rhene formoa is endemic to Guinea.^[1] The holotype lives in the Guinea Highlands at an altitude of 1,550 m (5,090 ft) above sea level in 1991. Other examples have been found in the local area. It lives on the ground amongst plants.^[2]