(modified from Berge & Vader 2005)
1. Pereonite 7 dorsally with a strong pointed tooth, mandibular incisors smooth........ Alexandrella australis (Chilton, 1912)
– Pereonite 7 dorsally smooth, mandibular incisors fully or partly toothed......................................... 2
2. Gnathopods 1 and 2 subchelate........................................................................... 3
– Gnathopods 1 and 2 simple.............................................................................. 4
3. Maxilla 1 outer plate with 26 setal teeth; gnathopods 1–2 lacking facial setae; pleonites 1–2 dorsally with weak ridge, pleonite 3 with low rounded tooth...................................... Alexandrella subchelata Holman and Watling, 1983
– Maxilla 1 outer plate with 40–45 setal teeth; gnathopods 1–2 densely setose; pleonites 1–3 dorsally with a well developed pointed tooth................................................................... Alexandrella setosa sp. nov.
4. Pleonites 1–3 strongly toothed, female pereopod 1 with oostegite................................................ 5
– Pleonites 1–3 weakly toothed, female pereopod 1 without oostegite.............................................. 6
5. Right mandible with lacinia mobilis reduced to a simple tooth............. Alexandrella mandibulata Berge & Vader, 2005
– Right mandible with lacinia mobilis broad and toothed, but smaller than left one... Alexandrella martae Berge & Vader, 2005
6. Mandibular incisors not toothed along the entire margin, antennae subequal.......... Alexandrella dentata Chevreux, 1912
– Mandibular incisors toothed along the entire margin, antenna 1 shorter than antenna 2......................................................................................... Alexandrella inermis Bellan-Santini & Ledoyer, 1986