Key to the species of Topalia

The following key is to adults, without the cerotegument present.

1. With the following combination of characters: notogastral ridges in an inverted T-shape; pair of condyles on interlamellar region of prodorsum; two pairs of epimeral foveolae present........ Topalia katyae sp. nov. (Australia, 347 × 213 µm; Fig. 6)

- Without the above combination of characters............................................................... 2

2. With single longitudinal notogastral ridge with pair of hollows laterally; with enantiophysis E2 (on epimeral border II) and enantiophysis V (on epimeral border III); interlamellar region with pair of acute condyles overhanging dorsosejugal suture................................................... Topalia africana Mahunka, 1985 (South Africa, 388 × 244 μm)

- Without the above combination of characters............................................................... 3......................................... Topalia problematica Balogh & Csiszár, 1963 (Argentina, 387 × 231 µm) - Without the above combination of characters............................................................... 4

3. With two pairs of longitudinal notogastral ridges; a longer median pair and a shorter lateral pair; with enantiophysis V (on epimeral border III); aggenital setae posterolateral of genital plate (slightly posterior and lateral to setae g 4)...............

4. With one pair of Longitudinal notogastral ridges curving medially, extending lateral and posterior of setae dm; at least some of setae of h and p series on squat tubercles; pedotectum I with teeth on anterior margin................................................................................... Topalia velata Hammer, 1966 (New Zealand, 350 × 221 μm)

- Without the above combination of characters............................................................... 5

5. With one pair of straight longitudinal notogastral ridges extending from anterior margin of notogaster as far as setae dm; interlamellar region with pair of short longitudinal laths extending from setae in to dorsosejugal suture, each terminating in a short, blunt condyle....................................... Topalia clavata Hammer, 1966 (New Zealand, 370 × 258 μm)

- Without the above combination of characters............................................................... 6

6. With one pair of longitudinal notogastral ridges strongly pinched or waisted (‘keyhole-shaped’) anterior of setae dm; with inverted V-shaped ridge in interlamellar region; setae le on anteriomedian edge of lamellae............................................................................. Topalia granulata Hammer, 1966 (New Zealand, 335 × 240 µm)

- With one pair of longitudinal notogastral ridges curving medially, narrow anterior of setae dm and expanding posteriorly around domed centrodorsal region.............................................................................. 7

7. Anteromedial edges of lamellae separated almost as far posteriorly as insertion points of setae in; (3) interlamellar region domed; anterior margin of notogaster transverse medially, then stepped posterior of bothridia; notogastral cerotegument of coarse irregular granules and tubercles overlaying fine pattern of angular foveolae...................................................................................... Topalia caliginosa sp. nov. (Australia, 370 × 226 µm; Fig. 1)

- Without the above combination of characters............................................................... 8

8. Anterior margin of notogaster curved, convex; cerotegument a network of large foveolae separated by angular ridges interspersed with minute granular tubercles; with series of parallel striae anterior of the genital plates............................................................................ Topalia dunlopi sp. nov. (Australia, 347 × 211 μm; Fig. 5).

- Anterior margin of notogaster indented; cerotegument lacking angular ridges; region anterior of genital plates smooth..... 9

9. Notogastral cerotegument of fine granules; epimeres III and IV appearing separated.................................................................................... Topalia corinnensis sp. nov. (Australia, 416 × 252 μm; Fig. 4)

- Notogastral cerotegument of coarse foveolae and minute tubercles; epimeres III and IV appearing partly fused..................................................................... Topalia royi sp. nov. (Australia, 353 × 205 μm; Fig. 7)