Key to species of sulcacitus group adapted from Rolston (1974).

The first couplet of the following key correspond to Rolston (1974) couplet 36.

1. Posterior margin of pygophore bissinuate, concave mesially in ventral view (Figs 11, 14); posterior region of ductus receptaculi proximalis dilated in a cup-like sclerotized structure (Figs 61, 62)........................................... 2

1’. Posterior margin of pygophore sinuate, convex mesially in ventral view or mesial third slightly sinuose (Figs 8, 17, 20); posterior region of ductus receptaculi proximalis straight, dilated or not, not sclerotized. (Figs 60, 63, 64).................. 3

2(1). Broad black carina anterolaterad of parameres on lateral wall of genital cup (Fig. 10); posterior margin of gonocoxites VIII slightly sinuose in posteroventral view (Figs 49, 50)............................................ E. olacitus Rolston

2’. Small black denticle anterolaterad of parameres on lateral wall of genital cup (Fig. 13) posterior margin of gonocoxites VIII strongly sinuose in posteroventral view (Figs 52, 53)......................................... E. palacitus Rolston

3(1’). Posterior margin of pygophore quite convex mesially in ventral view (Fig. 6); laterotergites IX surpassing dorsal band that unites laterotergites VIII in posteroventral view (Figs 46, 47)................................ E. corcovacitus Rolston

3’. Posterior margin of pygophore slightly sinuose in ventral view (Fig. 15, 18); laterotergites IX not surpassing dorsal band that unites laterotergites VIII in posteroventral view (Figs 55, 56, 58, 59)............................................. 4

4(3’). Inferior layer of ventral rim concave mesially in posterior view (Fig. 16); posterior margin of gonocoxites VIII mesially deeply concave (Figs 55, 56)................................................................. E. sulcacitus Rolston

4’. Inferior layer of ventral rim mesially tumescent in posterior view (Fig. 19); posterior margin of gonocoxites VIII mesially slightly concave (Figs 58, 59).............................................. E. tacitus Bianchi & Grazia sp. nov.