ONYCHIURIDAE Börner, 1901

Beruete, Enrique, Arbea, Javier I., Baquero, Enrique & Jordana, Rafael, 2021, The family Onychiuridae (Collembola) from karst caves of the Basque biospeleologic district, with description of four new species, Zootaxa 5040 (2), pp. 151-194 : 154-155

Family ONYCHIURIDAE Börner, 1901

Key to the genera of Onychiuridae of the Basque bio-speleological district

1. Posterior cephalic pso absent. Furca reduced to two knobs with chaetae. Body fusiform.................... Kalaphorura

- Posterior cephalic pso present. Furca reduced to a tegumentary fold or a finely granulated area with posterior microchaetae. Body oval-elliptical................................................................................... 2

2. Cephalic chaeta d 0 absent. PAO with simple vesicles. Furca reduced to a tegumentary fold with 2 + 2 microchaetae................................................................................................. Protaphorura

- Cephalic chaeta d 0 present. PAO with composed vesicles. Furca reduced to a finely granulated area with 2 + 2 posterior microchaetae............................................................................................. 3

3. Abd III sternite divided into two subsegments, each with chaetae................................... Spinonychiurus

- Abd III sternite not divided............................................................................. 4

4. Tibiotarsus with 11 chaetae on distal verticil................................................... Deharvengiurus

- Tibiotarsus with 9 chaetae on distal verticil................................................................ 5

5. AbdV with 5−6 paired pso arranged in three rows............................................... Micronychiurus

- AbdV with a fewer number of pso, arranged posteriorly in one row............................................. 6

6. With anal spines............................................................................. Onychiurus

- Without anal spines................................................................................... 7

7. AIIIO with 5 papillae and curved guard sensilla................................................ Deuteraphorura

- AIIIO with 4 papillae and straight guard sensilla................................................ Orthonychiurus