Austrarchaea milledgei Rix & Harvey 2011

Austrarchaea milledgei is a species of spider in the family Archaeidae. It is endemic to Australia.

Holotype male: Total length 3.08; leg I femur 2.73; F1/CL ratio 2.51. Cephalothorax dark reddish-brown; legs tan-brown with darker annulations; abdomen mottled grey-brown and beige, palest posteriorly, with darker reddish-brown dorsal scute and sclerites (Fig. 23B). Carapace tall (CH/CL ratio 2.12); 1.09 long, 2.31 high, 1.05 wide; ‘neck’ 0.53 wide; bearing two pairs of rudimentary horns; highest point of pars cephalica (HPC) near posterior margin of ‘head’ (ratio of HPC to post-ocular length 0.87), carapace gently sloping and almost horizontal anterior to HPC; ‘head’ not strongly elevated dorsally (post-ocular ratio 0.26) (Fig. 9E). Chelicerae with dense tuft of accessory setae on anterior face of paturon (Fig. 23C). Abdomen 1.54 long, 1.13 wide; with three pairs of dorsal hump-like tubercles (HT 1–6); dorsal scute fused anteriorly to epigastric sclerites, extending posteriorly to first pair of hump-like tubercles; HT 3–6 each covered by separate dorsal sclerites. Partially expanded pedipalp (Figs 23D-E) with rounded-rectangular, broadly-tapered conductor; tegular sclerite 1 (TS 1) long, spiniform, visible in retro-ventral view; TS 2 spur-like, shorter than TS 1, partially obscured by TS 3; TS 2a sinuous, filiform, exposed distally; TS 3 rectangular, embedded within distal haematodocha, overlying proximal embolic sclerite and TS 2. Female (WAM T112568): Total length 3.74; leg I femur 2.96; F1/CL ratio 2.24. Cephalothorax dark reddish-brown; legs tan-brown with darker annulations; abdomen mottled grey-brown and beige (Fig. 23A). Carapace tall (CH/CL ratio 2.02); 1.32 long, 2.67 high, 1.23 wide; ‘neck’ 0.65 wide; bearing two pairs of rudimentary horns; highest point of pars cephalica (HPC) near middle of ‘head’ (ratio of HPC to post-ocular length 0.59), carapace gently sloping posterior to HPC; ‘head’ not strongly elevated dorsally (post-ocular ratio 0.21) (Fig. 7L). Chelicerae without accessory setae on anterior face of paturon. Abdomen 2.10 long, 1.41 wide; with three pairs of dorsal hump-like tubercles (HT 1–6). Internal genitalia with dense cluster of ≤ 15 variably shaped spermathecae on either side of gonopore, clusters meeting near midline of genital plate (Fig. 23F); innermost (anterior) spermathecae longest, sausage-shaped, curved antero-laterally; outermost (posterior) spermathecae bulbous; other spermathecae variably pyriform, mostly straight, directed antero-laterally. Variation: Males (n=2): total length 3.08–3.23; carapace length 1.09–1.10; carapace height 2.21–2.31; CH/CL ratio 2.00–2.12. For female variation see Remarks (below).

Austrarchaea milledgei is known only from rainforest and mesic closed forest habitats on the Barrington Tops Plateau, in the Barrington Tops National Park and Barrington Tops State Forest, New South Wales (Fig. 41). A juvenile specimen from Chichester State Forest and a single female specimen from Gloucester Tops may also belong to this species (see Remarks, below).