PLS of 1st to 3rd instars of Australomimetus djuka and 1st to 4th instars of Australomimetus spinosus. A–C. A. djuka. D–L. A. spinosus. All spigots in (A–E, G) are non-T-AAC spigots. AC spigots between two white curves in (F, H, I, L) are non-T-A; remainder are T-A. E, F.AC spigot complements in 2nd instars of A. spinosus: three non-T-A (E) (88%, N = 26 PLS); three non-T-A, one posterior T-A (F) (12%). G–I.AC spigot complements in 3rd instars of A. spinosus: four non-T-A (G) (13%, N = 30 PLS); four non-T-A, one posterior T-A (H) (63%); four non-T-A, one anterior T-A (not shown) (3%); four non-T-A, one posterior T-A, one anterior T-A (I) (20%). One posterior AC tartipore (G, magnified in inset) observed in 7% of 3rd stadium PLS; the rest had none. H.CY spigots (C) first appeared in 3rd instars of A. spinosus. J, K.AC spigots on PLS from different A. spinosus specimens, showing larger diameter openings on T-AAC spigots (arrows) compared with neighboring non-T-AAC spigots [see Results (‘PLS’)]; measurements given in nm [see Materials and methods (‘SEM of spinnerets…’)]. L.PLS containing possible phylogenetic nubbin, adjacent to putative sensillum (S), in position consistent with araneoid AG-FL spigots. Lower inset, same nubbin (N) and sensillum magnified, anterior view; upper inset, sensillum from opposite PLS, lacking a nubbin; circles indicate (indistinct) raised-rim pores that are part of sensilla. More distinct pores can be seen in Townley and Tillinghast (2009) figs 8I, 9D, 13K, 20B, 22C and Townley et al. (2013) figs 2G, 4G. Unlabeled arrows point to AC tartipores, one anterior, one posterior, indicating an AC spigot arrangement during preceding (3rd) stadium like that shown in (I). D, E, G, I–K, L upper inset. Left PLS. A–C, F, H, L main, L lower inset. Right PLS (image flipped). C, CY spigot; S, putative sensillum. Scale bars: A-I, L 20 µm; J, K 5 µm. See also Abbreviations and terminology (‘Spinning apparatus abbreviations’) and Results (Convention 3 in ‘Conventions applied…’).