A key to the species of Prionopetalum

This key builds extensively on previous keys provided by Kraus (1960) and VandenSpiegel & Pierrard (2009).The new species described here is included, but Aquattuor fasciatus is excluded, and P. stuhlmanni is treated as a synonym of P. kraepelini (cf. above). I follow VandenSpiegel & Pierrard (2009) in not considering Spinotarsus werneri Attems, 1910 as a species of Prionopetalum, although Kraus (1960) suggested such a relationship (but still listed S. werneri under ”species incertae sedis ”).

1. Coxa with a straight, mostly long lateral spine pointing basad, laterobasad or laterad (Fig. 9 A –L) ......................................................................................................................................................2

– Coxa different, sometimes with another type of lateral process, but not a straight basad, laterobasad or laterad spine.................................................................................................................................13

2. Lateral coxal spine directed laterad, set off by right angles from main coxal margin (Fig. 9 A) ...... ......................................................................................................... P. megalacanthum Attems, 1912

– Lateral coxal spine different.............................................................................................................3

3. Lateral coxal spine directed basad, in part overlying main body of coxa (Fig. 9 B) ....................... ............................................................................................................. P. frundsbergi (Attems, 1927)

– Lateral coxal spine different.............................................................................................................4

4. Tip of distal telomere process (tdp) divided into two equal branches (Fig. 10 A). Gonopod coxa profile as Fig. 9 C ............................................................ P. bifidum VandenSpiegel & Pierrard, 2009

– Tip of distal telomere process not divided into two equal branches, but one or two small subapical processes may be present..................................................................................................................5

5. Distal telomere process (tdp) ending in three dark spines (Fig. 10 B). Gonopod coxa profile as Fig. 9 D ................................................................................................ P. tricuspis Brolemann, 1920

– Tip of distal telomere process at most with a single accessory process/spine...........................6

6. Proximal telomere process (tpp) distally expanded, asymmetrically club-shaped (Fig. 11 A –F)......7

– Proximal telomere process not strongly expanded distally (Fig. 11 G–K).......................................12

7. Distal telomere process (tdp) with a small accessory process (Fig. 10 C)....................................8

– Distal telomere process without accessory process (like Fig. 10 D).............................................9

8. Lateral coxal spine relatively short, directed almost basad (Fig. 9 E). Proximal telomere process (tpp) moderately asymmetrical (Fig. 11 A) ............................................. P. aculeatum Attems, 1914

– Lateral coxal spine directed almost laterad (Fig. 8 F). Proximal telomere process strongly asymmetrical (Fig. 11 B) ............................................................. P. ndelei VandenSpiegel & Pierrard, 2009

9. Coxa mesapically rounded (Fig. 9 G). Proximal telomere process as in Fig. 11 C ............................... ...................................................................................................................... P. serratum Attems, 1909

– Coxa mesapically with a spinous projection (Fig. 9 H–J, arrows)................................................10

10. Distal margins of proximal telomere process (tpp) smooth (Fig. 10 D). Gonopod coxa profile as Fig. 9 H .................................................................................................. P. dentigerum Verhoeff, 1941

– Distal margin of proximal telomere process wavy or with a denticle (Fig. 11 E–F).........11

11. Distal margin of proximal telomere process (tpp) wavy (Fig. 11 E). Gonopod coxa profile as Fig. 9 I ............................................................................................................. P. tanganjikum Verhoeff, 1941

– Distal margin of proximal telomere process with a single denticle (Fig. 11 F, arrow). Gonopod coxa profile as Fig. 9 J .............................................................................. P. xerophilum (Carl, 1909)

12. Proximal telomere process (tpp) straight, apically rounded (Fig. 11 G). Body diameter 5.5 mm. Gonopod coxa profile as Fig. 9 K ..................................................... P. clarum (Chamberlin, 1927)

– Proximal telomere process slightly curved, pointed (Fig. 11 H). Body diameter 3 mm. Gonopod coxa profile as Fig. 9 L .............................................................................. P. pulchellum Kraus, 1960

13. Coxa with a strongly curved lateral spine (Fig. 9 M–N)............................................................14

– Lateral coxal spine, if present, not strongly curved.....................................................................15

14. Gonopod coxa profile as Fig. 9 M. Body diameter 2.5 mm ............ P. etiennei Damange, 1982

– Gonopod coxa profile as Fig. 9 N. Body diameter 3.3–3.8 mm ........................................................ ............................................................................................ P. lindi VandenSpiegel & Pierrard, 2009

15. Lateral coxal spine sizeable, directed apicad and partly overlying main body of coxa. Coxa apically bifid (Fig. 9 O–Q)...............................................................................................................16

– Coxa at most with a tiny lateral spine or bump (Fig. 9 R–W).............................................18

16. Both apical branches of coxa pointed, the mesal branch hook-like (Fig. 9 O) ................................ ................................................................................................................... P. coronatum Kraus, 1958

– Mesal-apical branch of coxa not pointed (Fig. 9 P–Q)...............................................................17

17. Gonopod coxa profile as Fig. 9 P ........................................................ P. exaratum (Attems, 1938)

– Gonopod coxa profile as Fig. 9 Q ............................................................ P. cornutum Kraus, 1958

18. Proximal telomere process (tpp) with several lobes along one side (Fig. 11 I). Gonopod coxa profile as Fig. 9 R ................................................................................. P. kraepelini (Attems, 1896)

– Proximal telomere process at most with a single lateral lobe (Fig. 11 J–K)..........................19

19. Coxal apex hook-like (Fig. 9 S). Body diameter 2.5 mm .................... P. glomeratum Attems, 1935

– Coxal apex not hook-like (Fig. 9 T–W). Body diameter 4.4–5 mm ............................................20

20. Coxal apex with three mesad processes (Fig. 9 T) ................................ P. urbicolum (Carl, 1909)

– Coxal apex with two mesad processes (Fig. 9 U–W)...................................................................21

21. Both mesad processes of coxal apex pointed (Fig. 9 U) ...................... P. suave (Gerstäcker, 1873)

– Subapical mesad process of coxal apex rounded (Fig. 9 V–W).....................................................22

22. Gonopod coxa profile as Fig. 8 V. Solenomere with a short accessory branch at c. ⅔ of its length. Proximal telomere process as Fig. 11 J. ............................................................ P. fryeri (Turk, 1956)

– Gonopod coxa profile as Fig. 8 W. Solenomere without an accessory branch. Proximal telomere process as Fig. 11 K ........................................................................................... P. asperginis sp. nov.