Mesembrinella bicolor species-group

Recognition. Anterior spiracle with broad oval opening above; disc of T5 without horizontal row of stout setae.

Male with epandrium moderate in size; surstylus and cercus in close proximity, tending to curve toward each other in lateral view (as in Fig. 63); only M. longicercus has both surstylus and cercus straight (Fig. 77). Surstylus usually with a distinct curve posteriorly, whereas the cercus is fairly straight except for forward-curving tip; phallus broad in dorsal view anterior to hypophallic lobes (as in Fig. 154); sternites typically broader at base (ST1) and usually progressively narrower and smaller distally (ST2–4), with ST5 bilobed as in Fig. 262 [in a few species, segments ST1–4 are about of equal width, Fig. 278]; T4 and T5 about equal in length.