Key to Brazilian species of Nallachius (modified from Penny, 1981)

1. In forewing, MP2 vein fused with CuA vein (Fig. 3 a) ................................................................................................. 2

1’. In forewing, MP2 vein not fused with CuA vein (Fig. 3 b)........................................................................................... 3

2. Forewing with apex rounded and RS vein five branched (Fig. 3 c) ........................................................... N. maculatus

2’. Forewing with apex plainly asymmetrical and RS vein three or four branched (Fig. 3 a).............................. N. adamsi

3. Labrum black, male genitalia with dorso-lateral plate of gonarcus (Fig. 4a).................................................... N. limai

3’. Labrum pale, male genitalia without dorso-lateral plate of gonarcus (Fig. 4 d)............................................................ 4

4. Dorsal lobes of ectoprocts approximated on midline (Fig. 2 a)..................................................................................... 5

4’. Dorsal lobes of ectoproct widely separated on midline (Fig. 4 c) ................................................................................. 8

5. Forewing with RS vein four branched. Genitalia: median lobe with apex forked (Fig. 2 c)............... N. furcatus n. sp.

5’. Forewing with RS vein five branched. Genitalia: median lobe with apex simple, only membrane forked (Fig. 4 b) .. 6

6. Most distal costal crossveins forked ................................................................................................................. N. ovalis

6’. Most distal costal crossveins simple............................................................................................................................. 7

7. Male genitalia with lateral projections of mediuncus pointed and gonocoxites lancet-shaped (Fig. 4 b)....... N. dicolor

7’. Male genitalia with lateral projections of mediuncus rounded and gonocoxites scimitar-shaped (Fig. 4 d) .................. .............................................................................................................................................................. N. phantomellus

8. Costal crossveins unforked ........................................................................................................................ N. infuscatus

8’. Many costal crossveins forked...................................................................................................................................... 9

9. Body flat black, forewing with wide brown bands....................................................................................... N. prestoni

9’. Body white with black tubercles, forewing with narrow brown bands .............................................. N. potiguar n. sp.