1. Peritremes terminate anteriorly far from bases of dorsal setae D 1 (Figs 1, 2); one macrosetae on leg IV (Fig. 12)......................................................................................... N. magnanalis (Thor, 1930)
- Peritremes nearly reach bases of dorsal setae D 1 (Figs 15, 16, 31); three macrosetae on leg IV......................... 2
2. Movable digit of chelicerae with two teeth (Figs 19, 20); spermatheca without cervix............ N. grumantensis sp. nov.
- Movable digit of chelicerae without teeth; spermatheca with long and thick cervix (Figs 35, 36).............................................................................................. N. ellesmerei (Chant & Hansell, 1971)