A key to the families and genera of Eutegaeoidea

1 Anterior region of humeral process in the form of a short, shallow triangle not extending as far as bothridia (Figs. 41n)................................................................................ Cerocepheidae … Cerocepheus

- Anterior region of humeral process long, pointed apically, extending anteriorly as far as bothridium (Figs. 41f–j) or to point between bothridia and lamellar apices (Figs. 41 a-e, k-m)...................................................... 2

2 Humeral process originating on anterolateral margin of notogaster (Figs. 41 a-e).................................... 3

- Humeral process originating on margin of notogaster at its widest part (Figs. 41 k-m)................................ 7

3 Humeral process waisted basally (Fig. 41 a-c); pedotectum I sub-rectangular in lateral outline; pedotectum II pointed or sub-rectangular; discidium pointed (Figs. 43 a-c).................................................... Eutegaeidae …4

- Humeral process broad basally (Fig. 41d, e); pedotectum I sub-rectangular in lateral outline; pedotectum II lobed or sub-rectangular; discidium lobed (Fig. 43d, e)........................................... Neoeutegaeidae fam. nov. ...6

4 Humeral process strongly curved, with distinct basal notch (Fig. 41c); lamellar cusp with long, incurved spine (Fig. 42c); notogastral setae of l and h series in centrodorsal position (Fig. 12a)................................... Neseutegaeus

- Humeral process more-or-less straight, with basal protrusion (Figs. 41a, b) or V-shaped plate (Fig. 41d); lamellar cusp pointed (Fig. 42b) or with two teeth (Figs. 42a, d).................................................................. 5

5 Lamellar cusp with single point (Fig. 42d); humeral processes narrow, thin, transparent, delicate (Fig. 41b)..... Atalotegaeus

- Lamellar cusp with two teeth (Fig. 42a); humeral processes not narrow or transparent (Fig. 41a)................ Eutegaeus

6 Lage mites (>700 μm long); notogastral setae of l and h series thin, setiform (Fig. 18a); humeral processes with rugose ornamentation (Fig. 41d).................................................................... Humerotegaeus

- Small mites (<350 μm long); notogastral setae of l and h series stout, curved, spiniform (Fig. 20a); humeral processes smooth or with globular cerotegument (Fig. 41e)......................................................... Neoeutegaeus

7 Humeral processes with large, pointed anterior lobe and with 2-4 smaller lobes of lighter cuticle positioned posteriorly........................................................................................ Compactozetidae …8

- Humeral process lacking posterior lobes.................................................................. 10

8 Lamellae fused with each other apically, folded ventrally and fused with rostrum; with ovoid foramina lateral of fusion with rostrum (Figs. 42f)......................................................................... Compactozetes

- Lamellae with short, blunt, free cusps with or without a translamella (Figs. 42g, h)................................. 9

9 Apices of humeral processes triangular (Fig. 41h); notogastral setae emerging from alveoli; dorsosejugal scissure transverse; pedotectum I with long apical spine, pd II large lobe (Fig. 43h)........................................ Sadocepheus

- Apices of humeral processes bilobed (Fig. 41g); notogastral setae on tubercles; dorsosejugal scissure convex; pedotectum I lacking long apical spine; pd II short spur (Fig. 43g)................................................. Hamotegeus

10 Humeral process short, rounded apically, extending only as far as bothridium; rostrum lobed or incised (Figs. 411, j)................................................................................ Bornebuschiidae fam. nov …..11

- Humeral process long, pointed apically, extending well anterior of bothridium; rostrum rounded, entire (Figs. 411, j)..... 12

11 Lamellae very long with sharp apices, extending well beyond rostrum (Fig. 42j)......................... Dicrotegaeus

- Lamellae not extending beyond rostrum (Fig. 42i)................................................. Bornebuschia

12 Lamellae fused apically (Figs. 42k,l, m); notogastral setae short, thin, positioned marginally or sub-marginally on convex notogaster (Figs. 35a, 36a)................................................................ Pterozetidae …13

- Lamellae separate, with free cusps (Fig. 43m); notogastral setae long, with spinose ornamentation, positioned marginally and projecting vertically from concave notogaster (Figs. 37a).................. Porrhotegaeidae fam. nov ….. Porrhotegaeus

13 Anterior of lamellae strongly concave (Fig. 42l); pedotectum I massive, with apical spine, lateral margin straight, longitudinal; pd II thin, pointed (Fig. 43l)..................................................................... Dudichella

- Anterior of lamellae convex or slightly concave (Fig. 42k, l); pedotectum I and pd II rectangular (Fig. 43k) or pd I with curved anterolateral projection and pd II narrow, pointed (Fig. 43l)............................................ Pterozetes