Key to males of species of Arcyphysa

1 Apicolateral processes length at least 4x length of coxopodites of gonopods (Figs 144–145)....... Arcyphysa nebo sp. nov.

-. Apicolateral processes length less than 4x length of coxopodites................................................ 2

2(1) Gonopods with coxopodites in lateral view subquadrate to irregularly stout, with length equal to or less than 2x width (e.g., Figs 133, 137, 139).................................................................................... 3

-. Gonopods with coxopodites in lateral view more or less rectangular or rod-shaped, with length exceeding 2x maximum width (e.g., 105, 118, 129)................................................................................... 7

3 (2) In ventral view, apicolateral processes on segment IX strongly curved, distally club-shaped (Fig. 134), coxopodites triangular; in lateral view, coxopodites sub-quadrilateral (Fig. 135)................................ Arcyphysa anaplasis sp. nov.

-. In ventral view, apicolateral processes tapered to acute apices or narrowly rounded apically, shape of coxopodites varied, not triangular in ventral view and sub-quadrangular in lateral view.................................................. 3

4(3) Harpagones each single, tapered (Fig. 141)........................................... Arcyphysa volsella sp. nov.

-. Harpagones each distinctly bilobed (e.g., Figs 132, 136)....................................................... 5

5(4) Coxopodites of gonopods sub-rectangular in ventral and lateral views (Figs 132–133)........... Arcyphysa acmea sp. nov.

-. Coxopodites of gonopods triangular in ventral view (Figs 136, 138).............................................. 6

6(5) Apicolateral processes on segment IX twisted, sinuous (Figs 136–137)....................... Arcyphysa tortula sp. nov.

-. Apicolateral processes on segment IX not as above (Figs 138–139)........................... Arcyphysa flinti sp. nov.

7(2) Phallic apparatus with parameres visible towards base; harpagones usually sharply and shallowly bifid apically (e.g., Figs 117, 122)............................................................................................... 8

-. Phallic apparatus without parameres; harpagones never bifid apically, sometimes cup- or spatula-shaped (e.g., Figs 104, 110)................................................................................................... 12

8(7) Ventral lobe of each apicolateral process on segment IX elaborately crescent-shaped in lateral view, with curves lined with spe- cialised setae (Figs 118, 120)........................................................................... 9

-. Ventral lobe of each apicolateral process not as above...................................................... 10

9(8) Apicolateral processes in lateral view bilobed, each with ventralmost lobe loosely crescent-shaped; tergite X covered with dense microtrichia (Fig. 118)....................................................... Arcyphysa caldera sp. nov.