The constellation array (a recently discovered sensory structure on the fixed finger of pedipalp; Fet et al., 2006) is analyzed for a large set of species belonging to four genera in the family Vaejovidae: Paruroctonus, Smeringurus, Vejovoidus, and Paravaejovis. It is shown that this structure is an important taxonomic character. Two distinct configurations are identified, a two-sensilla array for Paruroctonus + Smeringurus + Vejovoidus and a three-sensilla array for genus Paravejovis, both differing from other vaejovid configurations so far investigated. The topology of these two array configurations are analyzed using landmark setae identified in this study.