A taxonomic analysis is proposed for the genus Lissothus Vachon, 1948 (Scorpiones, Buthidae). Two species have been described by Vachon, namely: Lissothus bernardi from Lybia and Lissothus occidentalis from Mauritania. These two species are considered as valid and distinct. A new genus and species, Pseudolissothus pusillus n. gen. n. sp., are described for Algeria. The two genera, Lissothus and Pseudolissothus n. gen., are associated in their general morphology by an almost total lack of keels on the body and pedipalps, but can be readily distinguished by different trichobothrial patterns. In Lissothus, the pattern is of the type A-ß, with a minorant neobothriotaxic and the absence of both d2 in the femur and esb on the fixed finger. In Pseudolissothus n. gen., the pattern is of the type A-a, orthobothriotaxic. Some comments on the geographical distributions of the two genera are also included.
Arachnida, Scorpiones, Buthidae, Lissothus, Pseudolissothus n. gen., Algeria, Sahara, new genus, new species.