Key to species of Neotachardiella gen. nov., based on adult females

1(0) Brachia and dorsal spine pedicel very long, each about 4x length of a brachial plate. Test very hard and brittle, orange to orange-brown; test of individual (not fused) adult females usually with 12 well-developed lobes, resembling a pitanga fruit (Fig. 2F–H).............................................................. Neotachardiella nangapire sp. nov.

– Brachia and dorsal spine pedicel short, each about same length as length of a brachial plate. Test hard or soft, not orange in color; test of individual (not fused) adult females usually with poorly developed lobes, never resembling a pitanga fruit.... 2

2(1) Total number of spiracular pores by posterior spiracle numbering usually 5 (range 3–8). First pair of marginal duct clusters (mdc-i) smaller than others, measuring 60–85 µm long, 48–75 µm wide, with 0–8 spermatoid ducts in subcircular-to-oval area (when present). Test hemispherical, with poorly developed marginal lobes, dull or only slightly shiny, purplish red to dark purplish brown (Fig. 2B and C)........................................................ N. charruarum sp. nov.

– Total number of spiracular pores by posterior spiracle numbering usually 11 (9–12). First pair of marginal duct clusters (mdc-i) larger than others, measuring 107–128 µm long, 80–95 µm wide, with 15–21 spermatoid ducts in subcircular-to-oval area. Test globular, shiny, light yellowish green in fresh specimens (Hempel, 1937: 8; not illustrated) but may become amorphous and dark in old specimens (Fig. 2A)............................................ N. ourinhensis (Hempel) comb. nov.