Key to the species of genus Iralunelus Burmeister of Argentina
1. Spiracles of 2º segment ventral and not visible from above........................ Iralunelus bergi Kormilev (Fig 2 D)
1’. Spiracles of 2º segment lateral and visible from above......................................................... 2
2. Postocular tubercles moderately developed; male pygophore large, acorn shaped; paratergites 8º reach up to 2/3 of pygophore; crenulation of the sides edges of the abdomen sligthly blurry................ Iralunelus subdipterus Burmeister (Fig 3 B)
2’. Postocular tubercles robust, male pygophore smaller; paratergites 8º reach up to 7/8 of pygophore; crenulation of the sides edges of the abdomen clear.............................................. Iralunelus monrosi Kormilev (Fig 3 A)