Key to the species of Ischnothyreus from Java and Sumatra

Key for females:

1. small lateral sclerites of postepigastric scutum present (e. g. Figs. 15 A, 68B)....................................... 2

- small lateral sclerites absent (e. g. Fig. 35 G)................................................................ 4

2. posterior spiracles connected by groove (Fig. 68 B)............................................ I. obscurus sp. nov.

- posterior spiracles not connected by groove, (e. g. Fig. 15 A)....................................................3

3. dorsal scutum weakly sclerotized and covering less than half of length of abdomen, postepigastric scutum less than twice as wide as long, winding tube elongated (Figs. 75 C–E)....................................... I. serpentinum Saaristo

- dorsal scutum more sclerotized and covering more than half of length of abdomen, postepigastric scutum more than twice as wide as long (Fig. 15 A).................................................................. I. ligulatus sp. nov.

4. eyes reduced in size (Fig. 60 D)...................................................... I. microphthalmus sp. nov.

- eyesize normal (Fig. 1 D–F).............................................................................. 5

5. dorsal scutum very small and weakly sclerotized (Figs. 51 E–H)................................... I. lucidus sp. nov.

- dorsal scutum longer than half of abdomen (Fig. 35 F)......................................... I. concavus sp. nov.