362 
M.S. Harvey 
the lack of definite apomorphies, even when the 
critically important larvae are taken into 
consideration. One of the most perplexing taxa is 
Wettina Piersig which was considered to be the 
sister-group of the remaining pionids by Smith 
(1976). I believe a case could be made for the 
removal of Wettina from the Pionidae and placing 
it closer to the aturid subfamily Frontipodopsinae 
(Harvey 1990). Even with Wettina removed, the 
remaining group of genera lacks autapomorphies 
and the task of delimiting the Pionidae remains a 
severe difficultly (Cook 1974, in particular the key 
on p. 26). 
Key to Australian species of Pionidae 
Males 
1. No segments of leg IV modified (Figures 8, 20, 
30); tarsal claws of leg III of similar size and 
shape...2 
At least one segment of leg IV modified (e.g. 
Figures 40, 62-64); tarsal claws of leg IH of 
different sizes and shape (e.g. Figures 39, 61) 
.5 
2. Three pairs of acetabula (Figure 5). 
. Larri laffa sp. nov. 
More than three pairs of acetabula (Figures 12, 
15, 25). Australotiphys .3 
3. Setae of tibia and metatarsus IV thickened 
(Figure 20); ventral shield present (Figures 
12, 14).4 
Setae of tibia and metatarsus IV not thickened 
(Figure 30); ventral shield absent, although 
with 2 pairs of lateralia (Figure 24). 
. Australotiphys barmutai sp. nov. 
4. Glandularia lgl and vg3 situated on ventral 
shield (Figure 14). 
... Australotiphys himonius sp. nov. 
Glandularia lgl and vg3 situated on dorsum 
(Figure 11) .... Australotiphys magnisetus Cook 
5. Metatarsus IV with dorsal blade-like 
expansion (Figures 40, 50); tibia of leg IV 
without dorsal concavity containing several 
stout peg-like setae (Figures 40, 50). 
. Acercella ..... 6 
Metatarsus IV not modified (e.g. Figure 62); 
tibia of leg IV with dorsal concavity 
containing several stout peg-like setae (e.g. 
Figures 62-64). Piona .7 
6. Dorsal blade like-expansion of metatarsus IV 
very thick (Figure 40) .. 
. Acercella falcipes Lundblad 
Dorsal blade-like expansion of metatarsus IV 
very thin (Figure 50).. 
... Acercella poorginup sp. nov. 
7. Genital field with deep central pit. 
. Piona cumberlandensis (Rainbow) 
Genital field without central pit (Figures 56, 
68, 80).8 
8. Pedipalpal tibia slender, lacking distinct 
ventral setiferous tubercles (Figure 99). 
.. Piona puripalpis K.O. Viets 
Pedipalpal tibia moderately stout, with distinct 
ventral setiferous tubercles (Figures 65, 76, 
88).9 
9. Pedipalpal tibia with distal thickened seta 
(Figures 65, 76); all acetabula incoporated 
into acetabular plate (Figures 56, 68).10 
Pedipalpal tibia with sub-distal thickened seta 
(Figure 88); only some acetabula 
incorporated into acetabular plate (Figure 
80). Piona murleyi sp. nov. 
10. Anterior claw of leg III without ventral clawlet 
(Figure 61). Piona australica K.O. Viets 
Anterior claw of leg III with ventral clawlet 
(Figure 72). Piona marchanti sp. nov. 
Females' 
1. Three pairs of acetabula (Figures 6, 37, 47).2 
More than three pairs of acetabula (Figures 18, 
28, 57, 70, 82, 94).4 
2. Excretory pore surrounded by sclerotized ring 
(Figures 35, 45). Acercella .3 
Excretory pore not surrounded by sclerotized 
ring (Figure 3). Larri laffa sp. nov. 
3. Pedipalpal tibia with 2 large ventral setiferous 
tubercles. Acercella poorginup sp. nov. 
Pedipalpal tibia with 2 small ventral setiferous 
tubercles. Acercella falcipes Lundblad 
4. Coxae fused in mid-line (Figures 17, 27); 
dorsalia and glandularia platelets large 
(Figures 16, 26). Australotiphys .5 
Coxae not fused in mid-line (Figures 59, 69, 81, 
93); dorsalia and glandularia platelets small 
(Figures 58, 92). Piona .6 
5. Ventral shield present (Figure 14). 
. Australotiphys himonius sp. nov. 
Ventral shield absent, although with 2 pairs of 
lateralia (Figure 27). 
. Australotiphys barmutai sp. nov. 
6. Pedipalpal tibia slender, lacking distinct 
ventral setiferous tubercles (Figure 100). 
. Piona puripalpis K.O. Viets 
1 Those of Australotiphys magnisetus Cook not known 
