Key to the species of the genus Caucaseuma Strasser, 1970

(based on the anterior gonopods of males)

1. Anterior part of angiocoxites with a pair of distal notches ............................................................... 2

– Anterior part of angiocoxites without a pair of distal notches .......................................................... 5

2. Anterior parts of angiocoxites with a pair of anterior triangular processes (Fig. 7H) ........................ .................................................................................................................... C. strasseri Antić sp. nov.

– Without such processes ..................................................................................................................... 3

3. Medial projection of anterior part of angiocoxites fused distally (Fig. 7C) ....................................... ..................................................................................................... C. minellii Antić & Makarov, 2016

– Medial projection of anterior part of angiocoxites not fused distally ............................................... 4

4. Lateral projections of angiocoxites distally rounded; smaller species, 11 mm (Fig. 7E) ................... .................................................................................................... C. kelasuri Antić & Makarov, 2016

– Lateral projections of angiocoxites distally in the form of elongated processes strongly curved posteriad; larger species, 16–17 mm (Fig. 7F) .................................... C. lohmanderi Strasser, 1970

5. Anterior part of angiocoxites with two distinctive, bifurcated, posterior projections/processes (see Antić & Makarov 2016: 31, fig. 20b, c, bp1 and bp2; Fig. 7A) ......................................................... .............................................................................................. C. elephantum Antić & Makarov, 2016

– Without such posterior projections/processes ................................................................................... 6

6. Anterior parts of angiocoxites with a deep V-shaped incision distally (Fig. 7B) ................................ ........................................................................................ C. fanagoriyskaya Antić & Makarov, 2016

– Anterior parts of angiocoxites without a deep V-shaped incision distally ........................................ 7

7. Margins of the anterior parts of angiocoxites circular (Fig. 7D) ........................................................ ........................................................................................... C. glabroscutum Antić & Makarov, 2016

– Margins of the anterior parts of angiocoxites subquadrangular (Fig. 7G) .......................................... ................................................................................................... C. variabile Antić & Makarov, 2016

To easily distinguish all eight species of the genus Caucaseuma, see also Figure 7.