Genus Monstrilla Dana, 1849

The two species studied here can be assigned to the genus Monstrilla by the presence of 1) a single urosomite between the genital double-somite and the anal somite, 2) well-developed fifth legs, with two ramal lobes usually carrying setae, and 3) six setae on each caudal ramus. This combination of characters is unique among the accepted genera of monstrilloids (Isaac 1975; Suárez-Morales & McKinnon 2014; Jeon et al. 2018).