Key to males of Nullana

1. Style (Fig. 10) cleft forming two rami..................................................................... 2

- Style (Fig. 30) not cleft, with single apex.................................................................. 3

2. Style (Fig. 10) with ventral ramus narrow, produced posterad as far as dorsal ramus, dorsal ramus three times wider than ven- tral portion............................................................... N. albinoi sp. nov. (Brazil - Paraná)

- Style (DeLong, 1976: 26, Fig. 4) very elongated, slender, with ventral ramus not produced posterad as far as dorsal ramus, dor- sal ramus the same width as ventral portion.................................................. N. huallaga (Peru)

3. Style (Fig. 30) with small tooth on ventral margin.......................................................... 4

- Style (DeLong, 1976: 26, Fig. 18) without small tooth on ventral margin......................................... 6

4. Style (DeLong & Martinson, 1980: 487, Fig. 29) with small tooth near apex of blade.................................................................................... N. gelbana (Brazil - Paraná [new record] and Santa Catarina)

- Style (Fig. 30) with small tooth near base or mid-length of blade............................................... 5

5. Style (DeLong & Martinson, 1980: 500, Fig. 40) with small tooth near base of blade............ N. alena (French Guyane)

- Style (Fig. 30) with small tooth near mid-length of blade...................... N. sakakibarai sp. nov. (Brazil - Paraná)

6. Aedeagus (DeLong, 1976: 26, Figs 14, 15) with processes near base or near mid-length of shaft...................... 7

- Aedeagus without processes............................................................................. 8

7. Aedeagus (DeLong, 1976: pg. 26 Figs 14, 15) with processes near base shaft, processes long, produced as far as shaft apex........................................................................................... N. deca (Peru)

- Aedeagus (DeLong, 1976: 26, Figs 16, 17) with processes near mid-length of shaft, processes short, not produced as far as shaft apex.............................................................................. N. sabora (Peru)

8. Subgenital plate (DeLong & Martinson, 1980: 500 Fig. 34) with acute apex.......................... N. verdana (Peru)

- Subgenital (DeLong & Martinson, 1980: 497, Fig. 19) plate with rounded apex................................... 9

9. Style (DeLong, 1976: 26, Fig. 8)with apex slightly curved dorsally; aedeagal shaft with apex not bent ventrally................................................................................................. N. scutella (Peru)

- Style (DeLong & Martinson, 1980: 497, Fig. 16) with apex abruptly curved dorsally; aedeagal shaft with apex bent ventrally........................................................................................... N. alera (Peru)